Why don’t more people use gas guns in the precision rifle world? I get asked that question a lot. Many military snipers use semi-automatic rifles for long-range work, but there isn’t a single shooter among the top 100 competitors in the Precision Rifle Series (PRS) using a semi-automatic rifle. Why not? Even though speed, maneuverability, and recoil management are huge parts to that game, the best shooters are all running bolt-action rifles. Some believe that is because AR’s can’t achieve the same precision as bolt guns, so the goal of this test was to quantify the precision difference between a couple of high-end gas guns and a custom bolt-action rifle.
6.5 Creedmoor Test Rifles
All of this started a few months ago, when I was contacted by Lewis Machine & Tool (LMT). They said they appreciated my tell-it-like-it-is, data-driven approach to testing gear, and they challenged me to compare their new large frame AR chambered in 6.5 Creedmoor to the best custom bolt-action rifle I had. Now that’s bold! I get approached to review all kinds of products, and virtually always decline … but their confidence definitely caught my attention.
A close friend of mine owns a large frame AR made by JP Enterprises, which is also chambered in 6.5 Creedmoor. That rifle was designed from the ground up for long-range precision work. So we thought it would be interesting to throw it into the mix as well, and see how it compared.
I looked for other precision AR’s offered in 6.5 Creedmoor to include in the comparison. The tactical, long-range competition world seems to believe that either 6mm or 6.5mm bullets are ideal maximizing hit probability for targets ranging from 400 to 1200 yards with minimal recoil (see the data). The 6.5 Creedmoor is a popular cartridge for that kind of long-range use, and we’re starting to see a few gun makers offer it as a standard choice on their rifles.
So I looked at other high-end AR manufacturers to see if they offered complete rifles in 6.5 Creedmoor, including: LaRue, Colt, Noveske, LWRC, POF-USA, GA Precision, Bravo Company, VLTOR, and Daniel Defense. Virtually all of them offer a large-frame AR-10, but most are only offered in .308 Win. So you could buy their complete rifle, but then you’d need to replace the barrel with one chambered in 6.5 Creedmoor for an apples-to-apples comparison. A few of them did allow you to specify other cartridges if you did a custom build. To my surprise, I only found one of those guys offering a 6.5 Creedmoor as a standard option, which was POF.
Our Brief POF Experience
Patriot Ordnance Factory (POF) did offer a 6.5 Creedmoor AR, and as luck would have it … a friend had one that only had a few rounds through it. However, we immediately encountered problems at the range with the POF rifle. Although we tried a few different types of factory ammo, the rifle wouldn’t consistently eject or feed rounds.
After talking to a few people about the problem, I uncovered that my buddy with the JP rifle had originally owned a POF in 6.5CM before he bought the JP … and he’d experienced virtually identical feeding issues with his POF. Our local gun store had sold many POF AR’s chambered in 6.5CM, and they had several customers return them with problems. I’ve been told that POF did repair each one and eventually get them in working order. But, we weren’t able to include the POF in the comparison because it had to be returned to the factory for repair.
The Final Line-Up
So here are the 6.5 Creedmoor precision rifles I was able to include in this comparison:
LMT Modular Weapon System (MWS)
Since Lewis Machine & Tool (LMT) was the catalyst for this whole project, I’ll start by looking at their black rifle.
The LMT rifle I tested was their Modular Weapon System (MWS) outfitted with a 24” stainless steel barrel chambered in 6.5 Creedmoor and 1:8 twist rate. The barrel is free-floated to maximize accuracy.
One of the cool features of the LMT’s Modular Weapon System is the quick-change barrel system. With an AR platform, it’s obviously easy to swap out the upper receiver to use another cartridge. But if you want that other upper to have the same fit and function, you either have to move your optics over or buy two identical scopes. It also might be ideal if you had the same handguard, rails, and accessories on the other upper receiver as well, which can get expensive. Sometimes when you swap uppers … you really just want a different barrel (for another cartridge, different barrel contour or length, etc.), and don’t necessarily want to swap all the other parts that are mounted to the upper receiver. Well, LMT has provided a way to swap the barrel out in just a couple of minutes. Whether you’re replacing a worn out barrel, or swapping to a different cartridge for training or mission-specific purposes … the end-user can do it in less than 5 minutes. LMT even includes all the tools you’ll need with the rifle.
In this design, the upper receiver just clamps around the shank of the barrel. So you just remove one screw, loosen another, and pull out the barrel. Insert the new barrel, and tighten both screws back up with the included torque wrench … and that’s it. You do need to pay extra attention to ensure there is no grease or debris on the shank of the barrel, and that it seats all the way in. But if you do that, you should be able to achieve the kind of precision this system was designed for. This is a similar to the approach Desert Tech uses on their bolt-action rifles, and they guarantee those to be sub-1/2 MOA (i.e. able to shoot groups under 0.5” at 100 yards with match grade ammo). So it’s a proven method to attach a barrel, even for precision work.
The LMT rifle features an uninterrupted, monolithic rail, which is conveniently indexed the full length of the rail. The monolithic rail allows you to mount optics and accessories in the ideal location, without having to avoid or bridge the area where the upper receiver stops and the handguard begins like you would on most AR platforms.
The handguard allows you to attach accessories at 12, 3, 6, and 9 o’clock. You wouldn’t be able to mount accessories at 45 degree positions without some type of offset adapter. Rails in a few sizes were included with the rifle.
This rifle came outfitted with LMT’s new DMR Buttstock, which is designed for the designated marksman. It features an adjustable cheek rest height and adjustable length of pull, which are high priorities for precision shooters. The flared angles on the cheek rest seemed to be more ergonomic for a natural shooting position and it helped me get a comfortable and consistent cheek weld. The DMR Buttstock also features a concealed picatinny rail on the bottom for mono-pod attachment. LMT claims the DMR buttstock was designed to replace current adjustable stocks in less than 20 seconds with no special tools required.
JP LRP-07 Long Range Precision Rifle
Now let’s look at JP’s offering in 6.5 Creedmoor:
JP Enterprises is well respected in the competition world, and for a good reason. Many gunsmiths use JP parts when building high-end custom AR’s, including parts like the JP trigger, low mass operating system, adjustable gas block, etc. Of course, those upgrades come standard when you buy a complete rifle from JP.
The specific model I tested was the JP LRP-07 chambered in 6.5 Creedmoor, which features a 22” barrel (my preferred length for this cartridge). It’s outfitted with a JP “Cryogenic Supermatch” barrel, which is described as a “medium” contour … but it is pretty thick compared to most AR barrels. The thick barrel definitely hints that this rifle was made for precision work.
JP offers a unique option they call a “Thermal Dissipater.” It is designed to keep the barrel cool through sustained fire, similar to how a heat sink on a computer processor keeps the chip from overheating. A heat sink is typically made from a highly thermally conductive metal like copper or aluminum, which encourages the transfer of heat from the source and spreads it over a much larger surface area to more effectively shed the heat into the surrounding air. In the case of the JP Thermal Dissipater, the heat sink increases the surface area by over 700%. JP says this can reduce the heat build-up near the chamber that causes throat erosion, which means the barrel could theoretically have a longer accurate life. It can also mitigate heat build-up in the handguard itself.
You can see the 2” tube handguard in the photo above, which is the JP Modular Hand Guard System. It’s 20% lighter than standard tubes, and unlike quad rails, it allows you to mount accessories in 45 degree increments all the way around. JP’s design is optimized for both comfort and function, with his philosophy of a “rail where you want them, not where you don’t.” The design seems similar to Magpul’s M-LOK system, but I don’t believe those two systems are compatible. JP does offer a ton of rail and accessory options for their handguard.
One of my favorite features on the JP rifle is the side-charging handle. JP explains this “self-folding, left-side charging handle affords additional leverage and makes it unnecessary to dismount the rifle to charge or clear it.” Some traditional AR shooters may hate the idea, but this setup seems fairly ideal for long-range work.
The upper receiver features an integral rail, which I’ve become a huge proponent of. As I’ve mentioned in other posts, I had lots of issues with one of my precision rifles that turned out to be related to slight movements in the rail the scope was mounted to. I sure enjoy the peace of mind an integral rail provides. Minimizing the number of parts and points of failure typically leads to better results.
The detail-oriented observer might notice this JP rifle is built on their streamlined competition upper receiver, which does not have a forward assist. They do offer a military version that has that feature, but their standard upper receiver does not.
And of course, the rifle comes with a crisp excellent JP trigger. It also features the JP Low Mass Operating System (LMOS), which reduces the felt recoil impulse.
One last thing to keep in mind is JP warns that their upper and lower receivers will not be compatible with other non-JP large-frame receivers. Of course, when precision is the primary goal, most shooters would likely go with a matched receiver set for a tight fit, instead of mixing and matching upper and lower receivers from different manufacturers.
This JP LRP-07 rifle as shown retails for $4,575 (when this was written). Keep in mind, this includes what JP calls a Presentation Grade Finish. To achieve this look they start by hand selecting a billet upper/lower combo that is hard coat anodized. Then they wet sand receivers by hand to give a brushed finish on the proud surfaces. They also apply a pristine polish to other parts like the barrel, hand guard nut, and a few other parts to match. That Presentation Grade Finish adds $800 to the cost and is purely aesthetic. This rifle starts at $3,299 with their standard black finish and options.
Surgeon Custom Bolt-Action Rifle
Since this is Precision Rifle Blog, and many of my readers prefer bolt-action rifles … I wanted to compare these AR rifles with a custom bolt-action rifle that was also chambered in 6.5 Creedmoor. I had Surgeon Rifles build this rifle for me just a few months ago as I was preparing for a huge barrel test. (The results from the barrel project are published in Bryan Litz’s new book, Modern Advancements Vol. 2.) But, this test was a great opportunity to use it as well!
This rifle is serving as our baseline for comparison, and isn’t the focus of this article … but I’ll just give a quick overview of the build:
- Action: Surgeon 591SA Repeater with TAC Knob
- Barrel: 22” Bartlein 5R Heavy Palma with 1:8 twist (Note: Although the photo above shows a fluted barrel, I actually used an identical barrel without flutes for this test)
- Chassis: Accuracy International AICS 2.0 with Victor Company ViperSkins
- Trigger: Jewell HVR set to 1 pound
As I mentioned, this custom bolt-action was built for me by Surgeon Rifles. Surgeon not only makes one of the best actions for a tactical precision rifle, but they’ve also been producing tack-driving complete rifle builds for the most demanding shooters (including USSOCOM and PRS champions) for more than a decade.
Honestly, this has become my favorite rifle. While a lot of that simply comes down to personal preference, I love just about everything about it.
This Surgeon custom rifle prices out at $5,134 as shown (excluding the bipod).
Shooting The Rifles
I started by breaking in and shooting these rifles a lot. I wasn’t sure if the LMT rifle had been broken-in, so I fired 300 rounds from it before I started the precision tests. I remember being impressed with the initial accuracy. During the break-in period, I fired 10 five-shot groups from the bench, which averaged 0.8 MOA. One of those groups was as small as 0.3 MOA, and the largest were a handful of groups at 1.1 MOA. I liked the ergonomics of the buttstock, and the trigger was better than most AR’s I’d used.
But unfortunately, I ran into some issues with the LMT rifle pretty quickly. The rifle would occasionally double-fire, meaning it would fire a quick two shot burst with one pull of the trigger. It originally only did that about once every 30 rounds, but over time progressed to where it happened every shot.
I contacted LMT about the issue, and they acted pretty surprised. After some digging, they uncovered the weapon they sent me was “a true T&E,” meaning it had been sent out for Testing & Evaluation to lots of people … and like a rental car, it may have seen some aggressive use. “So while the barrel is new, I believe the trigger and bolt carrier group (BCG) have upwards of 10,000 rounds,” they explained. So they mailed me a new trigger and BCG. Unfortunately, the replacement trigger wasn’t as light and crisp as the original … but it never double-fired, so I guess I’ll opt for safety and reliability over a lighter trigger. I do think we may have been able to shoot the LMT rifle a little better if it’d had a lighter trigger. I considered replacing the trigger with one of my after-market triggers, but then I’d be testing a customized rifle and not a LMT rifle … so I stayed with their stock setup for the rest of the test.
My buddy had already put a few hundred rounds down his JP LRP-07 rifle, but I shot it some prior to the precision test to get used to it. It was a pleasure. The trigger on it was as good as any AR trigger I’ve ever pulled. Now don’t get me wrong, it was a far cry from a light, crisp Jewell trigger on a bolt-action. But, it was a great single-stage AR trigger with a 3.5 pound pull and very little slop. The low mass BCG did seem to reduce perceived recoil. If I fired the JP and LMT blindfolded, I believe I could’ve told you which one the JP was purely based on the lighter recoil … but it wasn’t life-changing.
I also broke in the Surgeon rifle by putting 100 rounds down the brand-new barrel. In my experience, a bolt-action rifle doesn’t require as long of a break-in period as a semi-automatic rifle. A bolt-action is a much simpler device, with far less moving parts. Oh … and the custom bolt-action was a pleasure to shoot. The trigger was 5-star. The chassis was extremely comfortable and the recoil was quick and felt “smooth.” If you’ve never shot a rifle with an AI chassis, you should. It’s hard to quantify, but the chassis just seems to pass the recoil really cleanly with very little vibration or deflection. This rifle did weigh a couple of pounds more than the others, so that helped mitigate the perceived recoil as well.
The recoil force is sharper on a bolt-action than the AR’s, because gas-operated semi-autos spread the recoil force over more time. (Learn more in this post on recoil.) But, the recoil on an AR is longer and seems “choppier” than a bolt-action. That is because there is mass moving inside the rifle to eject the spent case and load the next round, and that cycling operation has distinct mechanical events that impact the amount of rearward force over time. (Watch a video illustrating the distinct events when an AR cycles.)
The Precision Test
To test precision of these rifles, I shot the rifles for groups at 100 yards. I used Hornady’s 6.5 Creedmoor 140gr A-Max Factory Match Ammo exclusively throughout break-in and testing. All of the ammo was from the same lot. My intent behind using factory match ammo was to ensure a level playing field, so you guys wouldn’t have to worry about variance within my handloads or if my handloads had been “tuned” to favor one particular setup.
Controlling For The Shooter
Then I also wanted to try to control for the shooter. One approach might be to shoot the rifles from a vise, and I do own one of those. But, in my experience I can get tighter groups firing from the prone position than I’m able to achieve from my vise. You may be as surprised as I was to learn that, but I’ve heard a couple other researchers say they had a similar experience. I’m sure there are great vises out there and guys who know how to get pinpoint precision out of them, but I guess I’m just not one of them!
So I elected the other approach for controlling for the shooter, and that is to average the results over multiple shooters. I recruited 3 other shooters to join me, and form the 4-man test squad. These other shooters weren’t just random guys off the street. One of them was my close friend, Rick, who consistently fires tighter groups than I’m able to coax out of a rifle. I’ve seen him shoot a sheet of 6 targets with 5 shots each, and every one of the groups measured under 0.25 MOA. I’ve seen him do longer strings where he puts 10 shots inside one 1/2 inch circle at 100 yards. Keep in mind that was done with a tactical rifle from prone … not a 25 pound, single-shot 6 PPC off a bench! Rick first entered the precision rifle world shooting high-end AR’s like those made by Les Baer Custom, and stuck to those for a year or two before buying his first bolt-action. So I’d bet he’s printed more tiny groups with an AR than anyone I’ve ever met.
The other two shooters are friends that are the gunsmiths at Mark’s Gunworks in the Dallas area, Mark and Chris. Mark’s experience has primarily been in the benchrest world, shooting in a DFW area shooting club with legends like Speedy Gonzalez. It was in that discipline that he acquired his impeccable (and almost paralyzing) attention to detail, and Chris has fully adopted Mark’s OCD tendencies when it comes to rifles. Both of them shoot in the local benchrest competitions, and both of them know what it takes to coax extreme precision from a rifle.
When you add me to that group, it rounds out our group of four shooters. We all gathered one day out at the range, and lined up all three rifles. All four shooters fired multiple 5 shot groups with each rifle. Some of us fired them from the ground in a prone position, and others fired them from a bench. I let the shooter go with whatever they were most comfortable with. The results are tallied up below.
The Results
Alright, alright. Enough talk. Let’s look at the results of the precision test. Instead of just showing one number to represent the average group size for each rifle, I wanted to show the range and variation of group sizes we shot. But, the challenge is there are typically one or two outliers that are either much smaller than the average or much larger than the average … so that can bloat the size of the range and make it less helpful. So I tried to represent the “typical group size” by showing the group sizes from the 25th to 75th percentile. That means 50% of the groups fall in the ranges shown, while the smallest 25% and largest 25% are excluded. This should give you a really good idea of what we experienced with these test rifles.
Now, I want to say a couple of things about the results. First, the lot of Hornady match ammo we used for this test (Lot #81494) had an abnormally high standard deviation (SD) in muzzle velocity of 19 fps. That was measured using a LabRadar Doppler Radar, which is accuracy to at least 1% of the measurement. For those less familiar with stats, an SD of 19 fps means that you could expect 95% of your shots to vary by up to 76 fps. That is a big number. If you used higher quality ammo or handloads capable of single digit SD’s, you’d likely be able to shrink those groups.
And I mentioned an issue I had with the LMT rifle where I had to replace the trigger, because the one on the evaluation firearm they sent me had excessive wear. Before I did that, I averaged 0.8 MOA 5-shot groups. LMT said they typically see these rifles hold 0.75 MOA or better, and my early results seem to support that. But, the replacement trigger was much heavier, and was honestly was no better than an average, factory AR trigger … meaning it left something to be desired. If you upgraded the LMT with a quality aftermarket trigger, then we believe we’d have shot that rifle better. We tried to coax the best precision we could out of the trigger they sent us, but the trigger can sometimes be the limiting factor … even if the rest of the rifle system is capable of more. We felt like that was the case here.
I was honestly impressed with the JP and thought it did well, although I’ve heard guys claim to get 1/4 MOA precision out of them. I’m not saying that is impossible, but I’ve just never personally witnessed a large frame AR capable of grouping 5 shots under 0.3 MOA for multiple successive groups. I bet I get to hear about some in the comments ;), but they seem rarer than the internet might lead you to believe!
And that brings us to the Surgeon. While the groups we recorded with the custom bolt-action weren’t anything to write home about, you can tell from the chart that they were measurably better than the AR’s. No huge surprise, but it’s interesting to see how much overlap there is between the bolt-action and the JP. I’m going to bet it surprises at least a few people to see how close an AR can come to the precision custom bolt-action rifle! Especially considering the Surgeon cost 36% more than the JP!
Let’s Put This In Context
Last year I wrote a series called “How Much Does It Matter?” and that included a post that looked at how much group size impacted hit probability on long-range targets. The results surprised a few people, including me. Look at the graph below, and notice that the increase in hit probability from using a 1 MOA rifle to 0.5 MOA rifle improves your odds by just 8% on the 10” circle at 700 yards, and by less than 4% on the 20” circle.
Don’t get me wrong, we all prefer tackdriving rifles. There is something innately satisfying when you stack 5 shots in one ragged one. But when you are comparing rifles like the JP (averaged ~0.7 MOA) to a Surgeon (averaged ~0.5 MOA), you’re just talking about a 2% improvement in hit percentage when it comes to these long-range targets. To learn more about where these numbers came from, read the post: How Much Does Group Size Matter?
It’d be ridiculous to expect every bolt-action to perform as well as the Surgeon custom rifle we tested, just because they operate with a bolt. We tested a factory Ruger Precision Rifle we tested a couple of months and it averaged 0.91 MOA five-shot groups with this same Hornady 140gr A-Max match-grade ammo (see that review). Not all bolt actions are created equal, and the one we’re comparing the AR’s to here is an example of a top-shelf, custom rifle. Just like these high-end JP and LMT rifles provide better precision than the average large frame AR (likely in the 1-2 MOA range), the Surgeon custom rifle doesn’t represent the average bolt gun. I mention that so we don’t mistakenly interpret these results as evidence that “bolt guns are superior to gas guns,” because that would just be ignorant.
This comparison can only really represent the three specific rifles we tested, and you could expect some variance in performance even with identical rifle of the same model. A larger test would need to be conducted with several randomly selected rifles of each model to draw more universal conclusions, but hopefully this test at least brings some objectivity to the conversation and puts some of these things into perspective.
Why don’t more people use gas guns in PRS matches?
I’ve been asked by a lot of people why more people don’t use semi-automatic rifles in precision rifle competitions. In fact, Bryan Litz asked me that exact question last year … so when a really sharp guy like that asks it, it’s clearly a good question! Honestly, I’m not completely sure. I’d bet if you put one of these AR’s in David Preston’s hands (the guy who won the PRS last year with the first perfect score) … he’d still do well in matches with it. Would he still win? Who knows! But, there seems to be enough evidence to show there are large frame AR’s available in the modern long-range cartridges like the 6.5 Creedmoor that are capable of competition level precision. I’ve still yet to see one that truly challenges the precision you can achieve in a custom bolt-action rifle, but the JP rifle we tested is clearly in the same ballpark and offers enough precision to be competitive.
A couple of months ago, I attended the 1st Annual Applied Ballistics Seminar Bryan Litz hosted in Michigan. One of the speakers was Shawn Wiseman, Director of the Precision Rifle Series (PRS), and he said he gets this question all the time too. He offered two major reasons he believed gas guns weren’t more popular in the PRS:
- Recoil impulse is longer, making it harder to spot impacts – Gas guns have a moving mass that must cycle back to the rear of the gun to eject the spent round, and then feed the next round into the chamber as it slams back home. That operation isn’t instantaneous, and it disturbs the rifle. Unfortunately, it is all happening during that short but critical time when the bullet is in flight. Shawn thought this longer recoil impulse on a gas gun can be a disadvantage in competitions like the PRS, because it can make it harder to spot your own impact. Seeing where your shot went is one of the most critical pieces of data a shooter can have. Even if you aren’t going to take a follow-up shot on that same target, knowing where you were off or exactly where you hit on the target can help you calibrate your wind call to increase your odds on the next shot.
- Risk of failure – While some gas guns are more reliable than others, bolt guns are much simpler machines with dramatically less moving parts. Before you call “B.S.” on this, realize Shawn is a special ops veteran who obviously has more experience with gas guns than most of us. So he is very familiar with their benefits and shortcomings when it comes to this area. While a gas gun may allow you to quickly put rounds down range, one malfunction during a match could destroy any chance of placing competitively.
Notice that Shawn didn’t even mention precision. Honestly, that surprised me at first … but considering the precision we found in our two AR’s, it stands to reason that raw mechanical precision may not be the limiting factor.
Conclusion
AR’s have radically improved over the past decade, in terms of both precision and reliability. That’s true for both AR-15’s and their large-frame brother. Computer-aided design and manufacturing, combined with a ton of competition in this space have pushed the industry forward. That’s why some believe it may just be a matter of time until AR’s catch up with the traditional bolt-action rifle. It’s still hard for me to imagine benchrest shooters firing gas guns, but nobody can predict what the market will do over the next 20 years.
There are certainly a lot of clear benefits of large-frame AR’s, and I hope this test showed that there are some GREAT options out there that are in the same league as a custom bolt-action rifle. There isn’t a clear, one-size-fits-all “right” answer, because the choice for what is the right tool for the job always comes down to application. Do you need the ability to make successive follow-up shots or more than 10 rounds of magazine capacity? Then you might lean towards the AR platform. Or do you want to eke out that last bit of precision, reliability, and ability to spot your own shots? In that case, you might lean towards a custom bolt-action.
The gap between the two setups just isn’t as large as it used to be, and seems to be closing tighter every year. I certainly appreciate all the effort the industry-leading manufacturers are throwing in this direction. Ultimately, that’s good news for us precision shooters, because it just means we have more great options!
Cal,
Great article as always! I’m really interested in the LMT in 6.5CM. Can you provide additional details on the barrel? I can only find 20″ 6.5CM barrels from LMT.
One short coming of the LMT system is the lack of the proprietary barrel extensions from LMT – if you want to spin up a custom barrel it requires a “donor” extension from another LMT barrel. Back in the early 2000s LMT made the extensions available for custom barrels but discontinued the practice for some reason (my guess is too many people ended up with poor shooting and unreliable barrels which looked bad on LMT so they stopped selling the extensions).
Cheers,
TT
That’s a great question, Tyler. I tried to find the exact setup they sent me on their website, and wasn’t able to either. Like you, I just saw a 20″ barrel in 6.5 Creedmoor, but the rifle they sent me to test has a longer barrel than that. Unfortunately, I couldn’t tell you anymore about it than what I’ve got in the post. You could probably give LMT a call and see what they say. I bet one of their reps reads this post within a couple days, so maybe one of them will chime in and enlighten us both! 😉
And I’m with you. I typically hate anything proprietary. But their quick-swap system has some merit, so I can see that it might be worth going proprietary for some applications. It is a shame they don’t offer those barrel extensions. That seems like it’d be a nice option, and some additional revenue for them. I appreciate the insight!
Thanks,
Cal
If I’m not mistaken the only difference in the barrel extension for the AR15 is one notch they mill in it for the proprietary clamp. I believe the AR10 is the same.
Interesting. I couldn’t tell you for sure, but there is a photo in the post of the LMT with the barrel out. You might could tell in that photo.
Thanks,
Cal
Awesome! …….!!! Thanks again Cal
I have to say your posts and testing criteria are the best I have seen. Love your data driven approach and how the data drives your descion making. I am building a 6.5 creedmoor and have been going back and fourth between bolt and AR. I have used your site and data to help guide me through the process. Thank you for all the good info, your site really helped me get comfortable trying to get into prescion shooting and informed me of what I was getting myself into.
You bet, Ron. I’m glad to hear that you’ve found the approach refreshing and content helpful. I try to just present the data and keep my own opinion out of it (as best I can). I’m thrilled I was able to play a small part in helping you get into this fun sport!
Thanks,
Cal
Cal- Great article. What caught my attention was that you said the Surgeon was your new favorite rifle. How does it compare to the 6XC you built? I figured that was the ultimate rifle. I was surprised to read you say this Surgeon was your new favorite. Can you comment on how they compare?
Thank you
Ha! Yeah, I thought that might catch some people’s attention. It took me a while to come to that conclusion. The AI chassis just feels a lot different than a stock. The recoil feels smoother. I also really like that I can adjust the butt plate vertically. It has flush cups on both sides on the rear and on the front. If I ever have to shoot offhand standing (which crazy match directors make you do in competitions occassionaly), I will sling up and I’ve found that attaching the sling to the opposite side (right side for me as a right-handed shooter) pulls and holds the rifle into my shoulder. It gives me more control, and feels more natural. I also like the grippy cheekrest, which is made from a rubber mold that keeps your face in the right place even when you’re sweaty.
Of course, I could install more flush cups on the Manners, and one of the Tubb 4-way adjustable butt plates … and I’ve definitely thought about it since using the AI. I do like the Surgeon bottom metal on my Manner’s stock better than the AI. It seems like the button to release the mag is ideal on the Surgeon (extends on either side of the trigger guard). The Manner’s is slightly lighter, but only by a few ounces. If I added that Tubb butt plate I’m sure they’d be virtually identical in terms of weight.
I think I might just prefer the flexibility and feel of a chassis. It’s not that I don’t like stocks. They have a place, but there are a few chassis that offer some compelling features. I’m probably about to try out either a KRG Whiskey 3 chassis or a MPA BA Competition chassis on my 6XC. I’ll probably go with a fixed stock to lighten the weight a little, and the idea of being able to have barricade stops, an extra rail under the foreend, additional QD flush cup mounts, and a couple other features make me want to give it a shot. Engineering on both of those chassis seems legit, so I’m on the fence on which direction to go. I think the MPA offers a few additional compelling features like the magwell cut, built-in bubble level, and angled section forward of the magazine that can help you get steady on barricades when used with a barricade stop. But the KRG is VERY lightweight (just 3.8 lbs), and has a LONG list of cool features, including all my must-haves. I may buy one of each and try them out!
And both of those rifles (the 6XC and this 6.5 Creedmoor) were built by Surgeon Rifles. They both have Surgeon 591SA actions as well, which is still what I prefer to use, although there are a number of great actions out there.
That’s probably way more than you wanted to know, but I hope it helps. The Manners Elite Tactical stock on the 6XC is still a great stock. It probably all comes down to application. And sometimes I just like trying new stuff to see what’s out there! I’m an incessant tinkerer!
Thanks,
Cal
Cal, something seems funny about the LRP-07 pricing
Base LRP-07 appears to be $3300
http://www.jprifles.com/1.2.5_LRP07.php
If you can get them for $1900, we need to talk ;D
Sorry, Bob! That was a good catch. I’ve been working on this post for a few months, so honestly I’m not sure where I got those numbers from. I want to say that was the price at one point, but surely that can’t be true. I might have just wrote it down wrong. You are definitely right. The rifle starts at $3299 now, and that rifle as configured is $4,575. I got the post updated to reflect that.
Thanks,
Cal
Cal – as always, great work, and a topic of particular interest to me
I just build an AR10 in 260 earlier this year specifically for tactical comps up here in Montana. I had been using a 300WM in an AICS chassis- great ballistic advantage, but I have been seeing more and more events where positional shooting (barricades, rock piles, roof tops) are becoming more common. Some stages (one notable one at Kettle Falls a few years ago which required 30 shots in 3 minutes) require fast shooting and follow up. And more and more, stages are requiring > 10 rounds. Not to mention, I had to shoot with perfect fundamentals to see through my shots. All of this led me to an AR10 with 24″ bbl in 260. It’s 6 ” shorter and 6# lighter than the 300, and better balanced to boot.
One critical item if you try this is an adjustable gas block. I went a step further and used a rifle length +2″ gas system, and JP’s low mass BCG. This combination dramatically reduces the recoil impulses, and makes for a very soft-shooting gun that you can see your shots through; and you can tune for excellent reliability. After finally getting the setting right (I started out way over-gassed) I’ve run 500 rounds without a single malfunction.
Disadvantages: You’re limited to smaller bullets like the Berger 130 AR Hybrid (the 140 gr class bullets won’t fit in a magazine). You can’t load to a specific jump- you load to a mag-determined OAL. You should religiously clean the BCG as often as possible. Gas guns and suppressors are not the best combo. But these are the only real disadvantages- as you point out, they’re more than accurate enough that your wind calls are far more important than the intrinsic accuracy of the guns (particularly if you’re hand loading). Speaking of which, I got about SD of about 4-6 in the 300WM, and with the same care and process am getting about 12-14 fps in the gas gun. As you observe, more moving parts means leas repeatability.
It is my new favorite gun. Out to 800 yds (where the majority of competitive targets are) its a very viable option.
Very interesting, Paul! Thanks so much for sharing. Your hands-on experience is invaluable, and definitely helps add to the conversation. It’s interesting to hear some of your points like bullet selection, cleaning, and SD’s. Those are things I hadn’t really thought about, but do all play into this as well.
And I’m with you. If you can master the positional stuff, and hit all the targets within 800 yards … you’d win just about every match out there. So many times we get distracted with trying to master pinpoint precision at 1000 yards or further, when other things might be more pertinent to your overall score.
Once again, thanks for sharing! It’s GREAT to get someone’s perspective who has experimented with both types of rifles in competitive matches.
Thanks,
Cal
im curious, where are you getting $1980 as retail price of the jp rifle? base price is 3299 on jprifles.com
Yeah, someone else pointed that out. I already corrected the post. Sorry about that.
Thanks,
Cal
Cal, have you seen any issues with failure to feed with 6.5 creedmoor? The shoulder taper is pretty extreme when it comes to a an autoloading rifle. At least to my eyes. I would think something like a 260 would feed better.
I can’t recall a single failures to feed with the JP and LMT rifles. Of course, the POF was a different story. But the other two seemed to have figured it out.
Thanks,
Cal
Great write up. I’ve had the luck to own an AI in 6.5 and have to say it was incredibly accurate. That being said, since you mentioned the comfort of the AI chassis wouldn’t it be nice to see an AI gas gun? Just a thought. Again another great article. Keep m comin!
Cal on more thing. Looks like both your gas guns were fitted with a break, at least the JP is and the LMT looks like a flash hider whereas the surgeon has no break. Could that affect accuracy, even if it’s in the fractions?
Chris, theoretically it could affect accuracy. The benchrest guys mentioned that, so I went back out and shot the LMT without a brake and there wasn’t a measurable difference in the results. If there was a difference, it seemed to be “in the noise.” But, that’s a keen observation. You could be right, although your probably talking a very small difference for well-made brakes (I’d guess less than 0.05 MOA impact on precision). So yes, maybe … but it’s in the fractions. I thought about testing them without the brakes, but then again … that’s how the companies shipped them out. I thought it was more important to test them as they came from the factory rather than try to mod in any way.
Thanks,
Cal
Yes sir. I love that rifle I have with the modded AICS chassis. It’s a pleasure to shoot. It’s hard to describe how it feels, but I thoroughly enjoy it.
That would be interesting if AI made a gas gun. I’m sure it’d be a good one if they put their name on it. But AI seems like a “do one thing and do it well” kind of company. They make tack-driving, world class bolt action rifles … and that’s it. They remind me of Schmidt & Bender. S&B makes world-class scopes. Unlike just about every other optic company, they don’t make binoculars, spotting scopes, rangefinders, or even t-shirts. They could leverage their brand to sell other products, but they have singular focus … and in my opinion that’s why they’re the best in the world!
Thanks,
Cal
Why don’t more people use semi-automatic rifles in precision rifle competitions? Aside from what Shawn Wiseman shared, another factor is the lock time of the fire-control group in an AR style rifle. Sure, shooting prone and very steady, there may be less difference between a bolt gun and a gas gun. However, when shots need to be made in compromised positions, when the crosshairs of the scope aren’t resting dead on the target, lock time begins to play a bigger difference in group size. I’m not sure any of us can actually perceive the movement between the instant we pull the trigger and the bullet leaves the end of the barrel. It is there, and the longer that time the larger the group.
Great point. There is a swinging mass when an AR trigger breaks, which is why I’ve heard some say you need to grip them a lot tighter (unlike a bolt gun). There is just a lot more moving parts when an AR fires, which makes it tougher to make every shot the same … especially from a compromised shooting position! Great point!
Thanks,
Cal
Well, here is another Christmas gift that is not going to happen:)
Ha! Same here, buddy. I don’t even own a large frame AR … but I think I found the one I should get if I ever do!
Thanks,
Cal
Cal,
This is a great article! I am a small custom manufacturer that is releasing our AR-10 this weekend on our website. http://www.patriotweaponry.us. This been a thought for quite sometime as to why PRS shooters have not been using these 6.5 gas guns! We are proud to say we are consistently getting 1/2 MOA out of Hornady 140 grain ELD Match factory ammo. I have been wringing out 1/3 MOA groups as well.
As for the triggers, we found that ATC Gold makes a fine drop in that breaks really clean at 3lbs. Ronin at ATC worked with us on making the hammer a little heavier to increase reliability.
It I had to perform a LOT of experiments to get the 6.5s to eject consistently as I was having problems because running a titanium bolt carrier really slams the bolt back and works some mischief on the old girls! With adding some tungsten weights to the buffer weight, and positive detent adjustible gas block on it, it leveled it out and functions great!
We are using a 20″ Proof Research barrel with a fixed Luth AR Stock. She weighs in at a very light 8lbs 14oz!
It’s 2016, time to ditch the old .308 and get with the times! Look for our offerings in AR10s on our websiteam this next week! Good stuff.
Happy pewing!
-Kody Karch
Hey, Kody. Thanks for chiming in. It does seem like you have to “tune” these to get reliability out of these and you’re always balancing that with precision. And yeah, I’m with you on ditching the 308 for these steel matches. The ballistics of the 6 and 6.5’s are much better, and have less recoil. When you don’t need the energy down range you’re just needlessly handicapping yourself. The market may head that way as more people get educated!
Thanks,
Cal
Cal,
Send me your info, I’d like to send the rifle out to you to try out!
Thanks,
Kody
I appreciate the offer, Cody. It shows you have confidence in your product. But unfortunately I won’t have the time to test any rifles in the near future. Wish I could.
Thanks,
Cal
Cal,
Spot on my man!!! I’ve been shooting the Desert Tech SRS A-1 for a few years now in both 300 WM and 6.5 CM. I recently purchased a Semi custom AR10 from Precision Firearms. (Web site listed below) https://secure.wf-api.com/www.precisionfirearms.com/m8/Sidewinder%20Advanced%20Carbon%20Type%20II–sidewinder-advanced-carbon-t-ii.html
I say Semi Custom because I picked the options and they made the gun for me… Took about 12 weeks to get it and now I’m about to go this weekend to shoot it… I have hand loads in Berger HT AR 130Gr / Berger HT 140Gr. Hornady ELD-X 143 Gr, and factory Ammo mostly in Hornady 143 ELD-X… I will be doing my 100 yard accuracy testing as well as speed testing…. I hope to get similar results as you did…. Thanks for the write up as it is perfect timing…..
Regards,
Very cool! I’d love to hear what you find, and if you end up preferring one over the other. Thanks for sharing.
Thanks,
Cal
Another gas gun consideration in PRS type matches is safety. There is alot fo movement between firing positions in a stage, often in a doghouse or other cramped position (pipes, tires, barrels, etc.). To be safe during movement with a bolt gun you can just open the bolt. TO be safe with a gas gun you need to lock the bolt back and possibly drop the mag. Takes more time and equipment to get back into firing readiness at the next firing point.
That’s true. Hadn’t thought of that either! Like you’re saying, it’s easy for an RO to see if a bolt gun is safe and a gas gun could cost you a few seconds more because of that. Might be enough to drop a point or two on a stage, which can make a big difference if you’re in the top 25%.
Thanks,
Cal
Great job Cal, good reading.
I remember back to 2012 or before that an Army Sniper team won the International Sniper Competition with a 308 Larue OBR. I don’t recall if this was a 308 only match or a any caliber competition.
I do know that when I get behind my SPR I have to re-educate myself on how to shoot it accurately. Your picture of the shooters set up reminded me of this.
Yes sir! I remember watching that competition myself. That OBR is an amazing piece of equipment. And you do have to adjust your style shooting an AR. I shoot bolt guns WAY more often, so it takes a while for me to reorient myself. That’s one of the reasons I fired so many rounds to break these rifles in. I’ve always heard that gas guns take longer to “break in”, so I fired 300 rounds each before I considered them ready for precision testing. But, I have to admit some of that was me practicing different techniques (like how tight or lose to hold the rifle, and different hand positions) to see what the rifles liked best. It seems like when it comes to bolt guns most guys have a similar style, but there are all kinds of theories when it comes to how to shoot AR’s accurately!
Thanks,
Cal
How about a test where you try different techniques (tight/loose hold, hand positions, etc) with AR’s for precision shooting? As you’ve stated there are all kinds of theories on this, but it would be interesting to test various techniques and see if there are any interesting findings.
Hey, Scott. That’s a good thought. It may vary by the shooter and weapon, which is why I was hesitant to publish what I found in my own testing. Ultimately, I tried everything from holding it like a bolt gun, to free recoil and only touching the trigger, and then gripping and pulling it into my shoulder with medium force, heavy force, and almost-popped-a-blood-vessel force. In my experience, the groups were the best with medium to heavy force. I was afraid that I was going to torque the rifle differently each time, so I tried to focus on making the hold identical each time. That’s is a lot easier to do with very light force that you use on a bolt gun, compared to some arbitrary amount of force on a gas gun. But, after hundreds of rounds of practice, I finally got pretty comfortable with it.
A more in-depth study might be interesting, but I bet it could vary by the shooter and I’m not sure how to quantify how tight you are gripping it or pulling it into your shoulder. You might could use force sensors, but then again those might also your grip in some way. It could be a valuable test knowing how many military guys are shooting gas guns. Now that I think about that, I’d be surprised if the military hadn’t already done some kind of similar testing … but it’s probably not published for guys like us to read!
Thanks,
Cal
Cal,
Another great article. I really enjoy your objective approach! Currently I am completing a master’s in analytics and was curious if I could help you run some more in-depth stats. Just looking for a fun way to combine my hobby and my profession. Let me know if I can help.
Will, I appreciate your comments. I actually do have a project that I’ve been thinking about where I could use some serious analytics. It’s still a couple months out, but I’d love to try to bounce the idea off you once it gets closer. I think you’d find it interesting!
Thanks,
Cal
Great article. I also had feeding problems on my AR10 build, then bought an adjustable gas block–problem solved. JP Enterprises barrel, bolt and low mass bolt carrier group.
Thanks for the hard work.
See there! You proved one of the points I made in the article. So many people use JP parts when building a custom AR! I know I chose some JP parts when I built my custom AR-15. They just make GREAT gear. In fact, the part I used on it was their low-profile adjustable gas block. They just make great stuff. And just to be clear, I paid full retail for anything I’ve bought for them and get no kick-backs or anything. Honestly, I’ve just never regretted buying something with “JP” stamped on it. These results just show how much attention to detail those guys have.
Thanks,
Cal
Very informative. I’m a firm believer the learning process never stops. Keep the data coming. My 6.5 Surgeon bolt gun built by GAP out preforms my Larue & two other off the shelf AR-10’s. Guess its a matter of preference.
Very interesting, Chris. It’s good to hear you had similar results with your high-end bolt gun and gas guns. That definitely corroborates the data we gathered here. Thanks for sharing.
Thanks,
Cal
Great article Cal. If you ever find yourself up Minnesota way try and get a hold of me and I’ll see about poking a few of my contacts over at JP. Anyways one thing that might have an effect on the reliability for a gun such as the POF is the gas port position or port size. I know that JP is using extended length gas systems in their 6.5 Creedmoor barrels, and a number of other manufacturers have tried to solve the problem by reducing the port size. The reasoning behind that is because the pressures at the port for smaller caliber rounds such as the 6.5 Creedmoor at say rifle length gas system positions are much higher than what the AR-10 platform was designed for. Because a number of companies didn’t take this into consideration they have run into a lot of issues such as what the POF rifle you spoke briefly about did. Personally I prefer JP’s method of moving the gas port to the point where the pressure is in spec rather than reducing port size. Regardless, in this day and age if you are going to try to use a gas gun for precision work an adjustable gas block is mandatory.
Very interesting, Don. Thanks for chiming in. I didn’t know about the differences in the length or port size … I just knew some seemed to work far better than others! 😉 I appreciate knowing more about the design behind it.
By the way … I read just about everything you guys publish over at Accuracy-Tech. I’m a subscriber, and love to see an email telling me you guys have a new post up. We both know how much work goes into a single write-up, so I appreciate what you guys are doing. Keep up the good work!
Thanks,
Cal
Cal it’s definitely a mutual admiration society. I love seeing the work you put into your site here. I’ve actually learned a lot from what you’ve done and really appreciate it. You’re definitely right there is a lot of work going into a single piece, but it’s a labor of love for me more than anything.
Anyways a good friend of mine works for JP, so I have a readily available source of information from them, and after a pleasant conversation with Criterion Barrels the other day where I asked if they were able to do an extended length gas system for an AR-10 I’m building I found out about reduced port size. The problems of pressure being out of spec for AR-10s in non-.308 Winchester based calibers is one of those things that’s not extremely widely known right now from what I’ve seen. But with the rise in popularity of alternative cartridges in AR-10 based guns it’s something that’s going to grow as an issue. This problem of port pressure is also one area where a bolt gun has an edge over a gas gun as well. It might be worth mentioning in the section you talk about the POF rifle and the problems you experienced with it.
have you considered a completely custom ar for doing something like this. there are some great options out there to mix and match with. i believe krieger will even fit a barrel for you these days. i was planning on building an ar-10 in the near future my self.
Honestly, I just haven’t had the opportunity to play with any full-custom, large frame AR’s. The JP is kind of semi-custom, but you don’t get to choose every single component, so it doesn’t really count. I’m not sure what you’d gain, because the JP uses what seems to be a great barrel and other parts. I’d suspect that a competent gunsmith “tuning” the specific rifle might could help squeeze out those last bits of performance and reliability, like what Kody said in the comments relating to adding some tungsten weights to the buffer weight and fine-tuning the gas block adjustment. At the end of the day, the muzzle velocity variance on the gas gun seem like it will always be higher than a bolt gun (because of all the moving parts inherent to a gas gun), which can erode some mechanical precision. But, like bolt-actions … a full custom rifle can be very satisfying!
Thanks,
Cal
Krug,
My customs are VERY satisfying! Can’t wait for my Web designer to get pictures up. Taking it out to shoot 1 mile at some steel today in the hands of a Army Sniper. Should be interesting!
Cal,
I have been looking forward to this article since you had told me about it in the spring when I contacted you about a 6.5 Creedmoor AR build I was planning. When you had mentioned that your two rifles were still both shooting under 1 MOA I was rather pleased and was hoping that if I could get to at least 1 MOA on my Frankenbuild I would consider it a success. I was able to get my rifle built in time to take a long range engagement class to learn how to shoot farther more accurately, I had only been able to shoot 11 rounds in the gun before taking the class to do an initial barrel break in (per Proof’s instructions) and the gun was still very unproven going into the class.
I am not sure how lucky I got with the build but after putting a couple hundred rounds into the rifle I am easily seeing .5 MOA accuracy out of the rifle and even out to 600 yards had a 3 shot group that was just over 3 inches.
I do think we are getting closer and closer to being able to reproduce the accuracy of the bolt gun but I think we are much farther away from changing the perception that gas guns can have a place in Precision shooting.
It is interesting to see what Falkor is producing with their 300 Win Mag Petra rifle with many mentions of .5MOA from each of their rifles and a full powered magnum round that is tamed very well in a gas gun.
Like most sports and society now-a-days, all it will take is the right shooter at the right event trying their gas gun and winning to get more people to think twice about what gun to use.
Thanks for putting out so much helpful information, you have been my number one source of knowledge when it comes to the Precision world, and you are the first place I tell me to immerse themselves in when they mention and interested in getting into the sport!
Thanks, Eric. Yeah, I’m excited to finally get this post published. I’ve been working on it for a while, but have had a lot of things come up that kept me from being able to put the finishing touches on it. I knew this could potentially be a charged topic, so I wanted to make sure I presented everything objectively and fairly, and didn’t want it to come across as “bolt guns are better than gas guns.” I do think some of the reason they aren’t used more is just dogmatic thinking. The precision crowd is slow to change their way of thinking, and I’m included in that group! So this was enlightening for me too.
I appreciate you sharing your experience with your gas gun. Sounds like you have a winner!
Thanks,
Cal
Awesome …. Cal, I print out your articles, take em to work to read on breaks, down time etc. Highlighter the stuff I want to research more when I get home from work . Lot of us are considering a bolt or gas gun in this caliber and discussion and research on the matter is popular. Can’t thank you enough for your ethical , professional work . I know that the length of time between your articles means good stuff is on the horizon, “wait for it” is well worth it every time. Thank You.
Regards from Panhandle ….Stay Safe !
Thanks, Caylen. Good to know you’ve found the content valuable and timely. Best of luck to you!
Thanks,
Cal
Cal, What were the average velocities from each of the three rifles using the Hornady ammo?
I enjoyed your review and I am conducting one of my own this year. I have been shooting local PRS style matches now for the last few years while using a bolt rifle. This year I assembled a precision AR in 6.5 Creedmoor with the intent to see if it would hold me back, give me an advantage or if my performance would remain the same…
That’s a great question! I was actually thinking about that question this morning. I probably have it written down, but I’m on vacation (which is why I had time to actually get this post up) … so that means I’m hundreds of miles of away from my log book. I did this test a few months ago, so I hope I still have it all written down. I’ll try to remember to check when I get home, and I’ll add a new comment here with the data if I can find it.
It sounds like a lot of us are thinking that direction. A few guys have chimed in with comments here. One of the fun things about PRS matches is they are all so different. Match directors can be really creative, and just when you think you’ve seen it all … they come up with something you couldn’t have dreamed of. That likely means there will be matches where it would be advantageous with a bolt gun and others where a gas gun might provide an edge. I know those Oklahoma boys like to shoot fast, so it seems like at least in some of those stages it might could shave a couple seconds or let you get in that one last shot.
“The Heatstroke” PRS match was this past weekend, and I had a couple friends in it. I asked them to count how many gas guns they saw, and they only noticed 3 out of about 170 competitors. So there are a few experimenting. I guess we’ll see how it shakes out!
Thanks,
Cal
I own the very JP rifle you tested, also in 6.5 CM. I had to go with a gas gun due to being in a wheelchair and not being able to stay in the gun while cycling the bolt. Been very happy but would like to add that hand loading or even buying match ammo for a gas gun is much different. The AR platform just can’t handle the pressures a bot gun can. Therefore velocities will not match the bolt guns. Also, all AR loads MUST drop feed in order to cycle correctly. I use a L.E. Wison chamber to check each round. This might be another reason for the adversion to gas guns. Thanks for all the great info as usual.
That’s an outstanding rifle, Jason. Glad to hear your enjoying it. That’s an application I hadn’t even thought of.
Thanks,
Cal
Cal:
Another good test. A good test always raises questions.
First the top level factors that control precision:
– Rifle
– Ammunition
– Sights
– Non-Shooter Components of Support
– Shooter – Human Components of the Support and Marksmanship
– Environmental Conditions
For this test the rifle-sight combination were identical for all shooters, presuming the rifle cleaning methodology was the same for all shooters or that it did not make a significant difference.
Hopefully the ammunition was identical in a statistical sense. That is, the manufacturing tolerance for the lot was such that the difference in mean and standard deviation of the muzzle velocity between samples had an insignificant influence on the group precision.
The non-human component of support differed in that some shooters used a bench and some prone position on the ground. I presume only one bipod was used on each of the rifles. Nothing was stated about support for buttstock. In any case presume this factor not significant.
The environmental conditions were not mentioned so presumably had no significant effect.
The remaining top level variable was the shooter. The human components of support include forearm traction, grip traction, cheek weld traction, shoulder traction and trigger traction. Most people would use term pressure rather traction and qualitatively that is OK. However, technically on the surface of an object there can be either tractions or displacements. Pressure is a particular state of stress. Stress exists inside a body and at a point represents the average of the local forces around that point. Traction is a vector and stress is a tensor.
The marksmanship components are the usual suspects – breathing, trigger control and the right tractions.
My question is what part of the differences in precision among the three rifles was due to the shooter? Call the shooters Mr. Blue, Mr. Green, Mr. Cyan and Mr. Magenta. Did Mr. Cyan have the most precise groups for all three rifles? Or did Mr. Blue for one, Mr. Green for one and Mr. Magenta for one. Underlying this question is the thought that some component of marksmanship is rifle-sight-non-human component of support independent but that some component can either by enhanced or degraded by ergonomics. And every shooter has different optimal ergonomics. Adjustable cheek pieces and LOPs should have permitted some, or the great majority, of ergonomic optimization for each shooter for each system but differences existed
One specific question. For your 6XC custom rifle you used a Harris bipod with LaRue QD mount and JEC spikes. For the Surgeon you used an Alamo 4Star Picatinny Rail and DLOC-S bipod. Why the difference? Different bipods for different stocks?
Rick
Great points, Rick. I try to think through these things systematically just like you before I start the experiment, and control for every thing I practically can. Ammo was all from the same lot. Cleaning solvents and methods were the same. Each shooter did shoot all three rifles the same way (i.e. If they shot one prone, they shot them all prone. If they shot from the bench, they shot all of them from the bench). We used the same bipod on each rifle throughout the tests. We did use standard rear squeeze bags. We shot all 3 rifles at the same time (shotgun start) and it only took about an hour to complete, so environmental conditions were the same.
As to the other points about the shooters preferences or differences in marksmanship … yep, all that stuff is true. That’s why I averaged it out over multiple shooters. The test definitely isn’t perfect, but I don’t think putting the rifles in a vise would tell you any more than what this test did. In fact, there might be more noise in the data or it could at least be skewed as much, if not more. At the end of the day, no experiment is perfect … but some are helpful. I feel like this one was.
The bipod was just something different I was trying out. I still prefer a Harris bipod, but have converted all of my rifles over to picatinny rails (not the sling stud), because I like a quick detach mount on my bipod. I also like spikes or some other type of feet that gets more grip than the rubber feet that are stock on the Harris. Alamo makes a semi-custom Harris bipod that features a quick-detach picatinny mount, and also had some after-market feet for the Harris that looked interesting. I ordered one to just see which I prefer. Both are good, but after lots of use … my favorite is still the bipod I showed on my 6XC post. I have changed one thing about it since then, which was taking off LaRue’s knob and replacing it with a Pod-Loc lever. So it started as a LaRue Harris bipod, then I replaced the feet with JEC spikes (Hawk Hill also makes some great feet that might even be better in some scenarios), and then I changed out the knob to a Pod-Loc. Ha! That’s a custom, custom, custom bipod! It’s a sickness, I know! I’m a incessant tinkerer! But now I know what I like. 😉
Thanks,
Cal
Cal:
Glad about the bipod because I just purchased a Larue-Harris and JEP spikes for my Blaser R8. I want to determine the 100 yard 10 shot group precision with factory ammunition in a Krieger Blaser 223 Rem Semi-Weight barrel. And test the precision of a bipod versus sandbags versus a competition bench rest for the front support.
Then people can comment on my methodology –hahaha!
Then will return to my true love which is shooting standing-offhand at 100 yards and trying to achieve 40 shot groups inside a 6″ diameter disk.
Rick
Cal:
You should use corp speak term CQI = Continuous Quality Improvement
Thanks, Rick
Cal:
Right on. The Litz factor short range system precision is easy to determine operationally. Go to the range and do itusing the support system you will use when shooting for “real”. The shooter is most definitely one of the variables. How many shots? Hmmm?
I am thinking of a system precision budget which is a function of the rifle-ammo precision budget, the sight precision budget, the support-shooter precision budget and the environmental precision budget. How to combine them? As a multivariate normal distribution? Do not know at the moment.
“Nichts ist so praktisch wie eine gutes Theorie.” Or regression curve.
Rick
I’m curious how a Seekins Precision 6.5 would have done. Too bad you didn’t get one of those in the mix
Hey, Kyle. Sorry, I didn’t even realize Seekins offers an AR in 6.5, or I would have considered it. It would have been cool to see how it stacked up.
Thanks,
Cal
I was a POF sponsored shooter for a short time years back.
The REAL disadvantage to a gas gun in PRS competition is the fact that most MD’s specify that movements during a stage must be made with the bolt open. This is pretty hard to accomplish in a timely fashion. I carried multiple mags on a stage, loaded with however many shots I could take at each position to move on an empty mag. I’ve even single fed a gas gun from an open bolt after transitioning positions.
You can see how this would really affect a shooter’s performance.
Absolutely. That’s a great point. Do you know if most matches still require that? I’d heard some rumblings of a change to that rule, but I wasn’t sure what the current state of affairs was. I know the rules could vary from one match to another, but I was hoping you (or others reading these comments) might give us some insight to what they’ve seen lately.
I appreciate you sharing your experience. A sponsored shooter that has used gas guns in competition is someone I’d want to hear from on this topic, so thanks for taking the time to share your thoughts.
Thanks,
Cal
Great article! I’m a mechanical engineer by trade, and I love the data that you guys put together for your articles. Real numbers makes decisions easy!
There are two reasons I always assumed made people steer clear of the semi-autos: Velocity variation and groups opening up over large strings of shots. Did you notice any velocity differences with your doppler system? Did the semi-auto rifles show a larger standard deviation in their velocities? Did you have the chance to fire large strings of shots (10-12) to see how the semi-autos fared? in the local PRS-style matches that I shoot in we’ll have stages that run over ten rounds.
Like I said, I’ve always assumed that was why but I’m curious to see if your tests proved/disproved that.
Thanks,
Matt
Hey, Matt. Glad you enjoyed the article. We did shoot long strings, because we were switching between rifles fairly quickly. A rifle was never sitting for longer than a couple minutes between strings, so I feel like if any of the rifles would have opened up as the barrel heated we’d have seen it. We didn’t notice any clear patterns of group sizes getting larger as the barrels heated up.
Now the question about the SD’s on the semi-autos was a great question. So good that I didn’t want to just ballpark an answer off the cuff. I went back and tried to dig up my notes, and found where I fired 10 shot strings from each rifle over the LabRadar. All of that was on the same day with the same lot of Hornady Match 140gr A-Max factory ammo. I put all those in Excel, and looked at the averages and the SD’s of the 3 rifles. The results surprised me. If all the barrels were the same length, you’d expect the bolt action to have the highest muzzle velocity. But the LMT rifle had a 24″ barrel and the other two were 22″ barrels. So maybe I’d expect either the bolt gun or LMT to have the highest muzzle velocity. Not the case. I’d also expect the bolt gun to have the lowest SD’s … also not the case. That’s why it’s so important to look at the data and not just talk about theories!
Here’s the data:
I wish I had this same data for some of my handloads. I’ve started using a Prometheus powder scale and consistently get muzzle velocity SD’s of 3-7 fps with very little effort. I’m afraid there is noise in this data. I calculated a standard error of 5.5-6.9 for those samples, where it would be 0.9-2.2 with SD’s of 3-7 fps. It’d just let you draw more clear conclusions on this. I used match-grade factory ammo from the same lot so that people wouldn’t question whether my handloads or loading techniques were part of the difference. I just try to think through what all someone might use to dismiss the results and then try my best to control for that, and match-grade factory ammo from the same lot was part of that.
So interesting question! You definitely peaked my interest. I’m not sure this data points to any conclusive answers, but it does make me question some of the long-held beliefs I’ve had about semi-autos compared to bolt guns. So thanks for triggering that!
Thanks,
Cal
Great Article Cal! Big fan of the quality that JP puts into their products but recently I’ve been put in touch with some guys out of Texas and let me tell you, TX Precision’s 6.5 Creedmore is the only one you will need in this category, out of the box and ready to roll. These guys are awesome! Check them out at (txprecision.net). They are super knowledgable and put out some high quality work on all of the TXP rifle lines. They have really done their homework when it comes to which parts play well together to get you the absolute most accuracy, durability and reliability out of your rifle. And on top of that they also do a lot of manufacturing work in house and will not stamp their names on it unless it’s perfect. I’m very happy with the work they’ve done for me.
Very interesting! I hadn’t heard of TX Precision, but I do see they offer 6.5 Creedmoor AR’s (which they call the TX-6Five) … with a bold claim of 1/2 MOA precision or better! I love it when a manufacturer is confident enough in their product to say something like that. Here’s what they say:
And those rifles are $2,999 … which seems like a screaming deal if they really live up to that. They seem to use quality components. They’ve definitely caught my attention. Here’s a photo from their website of the TX-6Five:
View the 6.5 Creedmoor Rifles on TXPrecision.net
They’re certainly a lot smaller of a shop than these others, but that doesn’t mean they can’t turn out a quality rifle. Thanks for sharing this with the rest of us!
Thanks,
Cal
Hi Cal,
I was notified of this article and was pleasantly surprised to see a customer of ours direct you to our site. I am the Co-owner of TX Precision. We are a small veteran owned shop, located just outside of Ft. Worth, TX. The accuracy guarantee is 100% true. The price is 100% true. I know you have already done the review. But I would like to send you our 6Five, so you can test and see for yourself. We would also love the honest feedback from you. We believe in our product. We also believe in trying to keep a top-tier precision system in the “affordable” price range. We are not a household name yet, so we welcome all challengers and skeptics. Let me know if you are interested, and we will send our 6Five out to you. Thanks Cal.
CB
info@txprecision.net
Hey, CB. I appreciate you reaching out. Unfortunately, I’m not at a place where I’d be able to dedicate the time to test out another rifle right now. I do appreciate the offer though. It shows you have confidence in your product. I bet if you consistently turn out a large-frame AR capable of 1/2 MOA accuracy or better, you’ll become immensely successful. I do wish you the best of luck. I’m in the DFW area occassionally, so maybe we’ll run into each other sometime and you can show me your product.
Thanks,
Cal
Have no experience in PRS but plenty in tactical and military sniper matches where team members often run a mix of gas and bolt gun.
In addtion to accuracy the bigger question is the difference is in velocity specially with handloads.For unsuported positions you would think that 5-6x longer lock time would greatly handicap the semiauto but it dosnt seem to be the case.
Question of delayed recoil , same issue with use of silencers on boltguns , muzzle brakes have noticably shorter impulse , specialy in larger calibers that is why i am supprised anyone uses a suppresor in PRS (add to that weight and lenght downsides are more than evident
Great points. I wish I had some data on the actual length of time we’re talking about when it comes to lock time, and recoil impulse for gas gun vs bolt.
I do have the data for recoil impulse of suppressor vs muzzle brake, because I collected all that in a very detailed way in my muzzle brake field test. On a 6XC tactical rifle, I recorded a recoil impulse that lasted 0.011 seconds with the popular APA muzzle brake (average over 3 shots). When I measured the recoil impulse on the same rifle, but with a Thunder Beast suppressor, it averaged 0.012 seconds in my experiment. I would expect that difference in time might grow with larger cartridges, but at least for the mid-sized 6mm and 6.5mm cartridges most of the guys are running there doesn’t appear to be a perceptible difference in the duration of recoil … at least in my experiment, which I know doesn’t perfectly emulate when a live person fires a rifle. That test setup wasn’t intended to compare the length of recoil, but I at least wanted to share whatever data I had that could speak to your comments. Not saying it’s conclusive, but maybe offers some perspective.
Thanks for the comments!
Cal
Locktime on rackgrade SR-25 is around 16ms on a rack grade rem 700 less than 3ms and on custom actions that is often in 2ms territory on benchmark T2K sub 1.5ms
But i expect custom actions to get ‘slower’ in the future as heavier firing pins and longer pin falls seem to promote better ignitiona and lower SDs
On .338 tactical guns suppresors impulse is noticablly longer than muzzle brake ,but yes like you suggested size does matter , gas ‘vloume’ from 90gn of powder and suppresor size and gas pathways are longer .
For me supressor is nice in terms of noise and partner position(with muzzle brakes you have to be much more in sync with your partner to avoid to many blasts in the face ,other thin suppresors make a 26+in barrel then well over 30 in OAL while a brake adds maybe 2 in
Cal, Thanks for another great article. I was very curious to see the results. I would have loved it if you would have tested an AR with a barrel made from the same company as the one on the bolt action, but hey I’m not fitting the bill so I won’t complain. I am almost more curious though on the muzzle velocities. I would love to know how much faster if any the bolt gun was compared to the gas ones and if you think there is enough of a statistical basis to say that the muzzle velocities on the bolt gun have a lower standard deviation.
Thanks,
Shawn
Hey, Shawn. Someone else asked a similar question int he comments, and it made me wonder myself. So I went and dug up the muzzle velocities out of my log book, and see what the averages and SD’s were for the different rifles. I don’t want to duplicate that in this response, but I just responded to some other comments on this post with those numbers. It is a great question! The data surprised me for sure. That might have been the biggest surprise from this whole test!
Thanks,
Cal
One reason I shoot bolt guns more often than gas guns is ease of cleaning. With a bolt gun I can just spray some foaming Wipe Out down the bore and patch it out a few hours later. A light wipe down of the bolt and a couple drops of lube and it’s done. We all know the fun of cleaning a direct impingement AR. Now that I have two kids my free time is limited and ease of cleanup helps me spend more time shooting. Thanks for another interesting article.
Yes sir! That’s a great point, Tim. Not only is cleaning more involved on a gas gun (because of all the intricate parts), but a gas gun usually demands a more frequent cleaning. One of the guys who won the PRS one year told me his competition rifle had 2000 rounds on it since it’s last cleaning! I’m not sure you’d get away with 1/2 that in a gas gun. But obviously, he didn’t struggle with reliability or precision on his bolt gun!
Thanks,
Cal
Interesting re the LMT trigger. I wonder if they just sent you a standard GI? My .308 MWS came with a wonderful LMT two stage trigger that is very very close to the Geissele SSA I have on a couple of my 5.56 rifles. In fact it is so close I never bothered to swap it out and as time passes it has only become better. My rifle has a 16″ chrome lined barrel but shooting the old M14 4895 load with 168 SMKs it is very solid at 0.75 to 1 MOA.
I have noticed over the years that a good trigger is very important to shooting ARs, especially the big frame ones. Many rifles I have shot have gained a half minute just from swapping the trigger! If you still have the rifle you may want to try a trigger swap if you haven’t already. It may not improve the spread on the low end, but it may improve it on the big end.
Ju
I’m not sure what trigger they sent me, but I agree 100% on the importance of a good trigger! I sometimes get asked what part is the most important to precision, and I’m usually torn on the barrel or the trigger. The barrel actually increases the mechanical precision of the rifle system, so I usually lean that way … but the trigger can increase the ability of the shooter to place shots precisely, and it’s hard to say which of those is more important!
Unfortunately, I don’t still have the rifle … LMT wanted that thing back! I do appreciate the offer. The original trigger was very light (despite the double-fires). So while I was waiting on them to ship me a new trigger, I would just load one round at a time. I averaged 0.8 MOA five-shot groups that way. In fact, the LMT rep said they typically see 0.75 MOA with that rifle/barrel when they test them at the factory. So I’d bet that’s what the rifle is capable of with a good trigger.
Thanks,
Cal
For anyone looking for more options for a factory 6.5 CM: https://lancer-systems.com/awc/modern-sporting-rifles/
Drew, those look very interesting! With a heavy Bartlein barrel, Geissele trigger, and other high-end parts … I’d expect those to be capable weapons. Looks like a 6.5 Creedmoor Long Range Tactical Rifle is priced at $4200, but looks ready for competitions out of the box!
Thanks,
Cal
I’ve heard great things about GAP’s GAP-10 G2 in 6.5. Too bad they couldn’t get you one to include in your head-to-head comparison.
If it has “GA Precision” stamped on it … I’d bet it shoots as good as just about anything out there. Honestly, I didn’t ask them if they’d send me a demo rifle … so I don’t want to say they wouldn’t or couldn’t get me one. I just tried to gather up whatever I could without having to wait on a custom build. Those guys might have loved to see their rifle in a head-to-head comparison like this, because I bet they shoot.
Thanks,
Cal
Cal:
Regarding the TXPrecision statment on accuracy. I suspect they mean precision rather than accuracy, presumably because the concept is once you have precision groups, producing centered groups is a piece of cake. Maybe it is, maybe it isn’t. And no mention of the number of shots in the group.
Rick
Cal:
As long as I am on a rant, what was the support the TX6-Five guys used? From my own experience in experimentation, your and other blogs, Litz’ books and Harold Vaughn I have formulated the grain of salt rule. The less the complete details accompanied by a proper statistical analysis the bigger the grain of salt to take with the conclusions.
Rick
I’m not sure what they used. I’d bet either a 3 or 5 shot group with factory match-grade ammo. But you could probably email or call them to find out exactly. I take it mostly as they believe in their product, and think you won’t be disappointed if you try one … so much so they’ll put it in writing. A lot of gunsmiths claim awesome results, but I’ve learned very few are so confident they’ll put it in writing.
Thanks,
Cal
Cal:
But they did state your mileage may vary! Make that precision.
Keep on shooting! Rick
How come your Surgeon has a 22″ barrel? Was it to reduce weight, better balance or handier to shoot from obstacles? My Surgeon from GAP in 6.5 CM came with a 26″‘ so I had assumed that length was optimal.
Great question. A 26″ barrel is very popular, and you won’t hear me say that it’s the wrong choice. It works well for lots of guys, and I’d bet most precision rifles come with a 26″ barrel. Most guys feel like that length optimizes their muzzle velocity, but that’s not always the case. I’ve been on a 22″ barrel kick for a 6.5 Creedmoor for a while, but I ran across an article recently on RifleShooter.com where they essentially started with a 27″ barrel on a 6.5 Creedmoor and chopped it off 1 inch at a time and recorded the resulting muzzle velocities. You can find the full article here, but here is some of the results for heavy-for-caliber bullets:
You can see they found a 24″ barrel to be the fastest, at 20 fps FASTER than a 27″ barrel. Compared to the 22″ barrel, there is only a 14 fps difference from the 27″ barrel, and it looks like a 28 fps difference compared to the 26″. You just don’t lose as much muzzle velocity as you might think. And some believe a shorter barrel will be stiffer and have less harmonics than a longer barrel. That’s why so many benchrest shooters run 20-22″ barrels. That’s also why Todd Hodnett (premiere trainer of military snipers) likes short, stiff barrels … or really long 30″ barrels on his magnums. He thinks anywhere in between is no man’s land.
But hey, I like the 22″ barrel because in the world of laser rangefinders … muzzle velocity just isn’t as important as it used to be. Does it really matter if I have to dial 4.0 mils or 4.2 mils?! Not really. In fact, I did a study on how much muzzle velocity can impact hit probability on long range targets, and found for the 6.5 Creedmoor you barely increase your hit percentage by 0.75% with each 25 fps increase in muzzle velocity! (See the data) Also, if I have a 22″ and then add a 7″ suppressor to it … I’m still only at 29″, which is very manageable (weight and maneuverability). A suppressor will also give me some of that velocity back, so I bet our velocities probably wouldn’t be a lot different with the same ammo. Honestly, there may be as much variation between two identical barrels.
Here is an article I wrote in 2013 about barrel length on the 6.5 Creedmoor, and it compares a 26″ barrel to the 22″ with and without a suppressor:
6.5 Creedmoor Barrel Length & Muzzle Velocity
It really comes down to personal preference. Most guys do prefer 26″, so you’re in good company. 50% of the guys in the top 100 finishers in the PRS are running 26″ barrels (see the data). Most of those guys could smoke me in a competition any day of the week. So who am I to argue?! But on the 6.5 Creedmoor, I just lean toward a 22″ barrel. I have several barrels in my safe right now chambered for 6.5 Creedmoor, and all of them are 22″. So I’m pretty convinced it’s the right call … for me. Apparently John Paul of JP Enterprises agrees with me, because that’s their barrel length for the 6.5 Creedmoor too. But that doesn’t mean 24″ or 26″ isn’t a good call either. Honestly, a lot of people make too much over barrel length. In my opinion, it just doesn’t matter as much as some might think. Everyone has an opinion on it though! 😉
Probably more than you wanted to know, but I bet you weren’t the only one thinking it … so I wanted to lay out the case.
Thanks,
Cal
Cal – I am new to your site and have read several of your great reviews and articles. A buddy of mine is in to the long range shooting competitions here in Washington state and I would like to give it a try too.
After reading the review of the Rem PSR Kit, took a quick gander at the EuroOptic.com site and see that they are having a 10% off sale on the Remington PSR Kit – still waaaaaay out of my league, but that is a good sale is someone was on the fence regarding a purchase. Tried to add comment to the PSR Review article, but looks like the comments are closed.
Anyhow, just an FYI for you or your readers, no need to post this comment.
Tried finding an email address for you but couldn’t find one.
Hey, Jason. Great to hear you’re going to give this a shot! I hope you enjoy getting into it as much as I have.
The Remington PSR Kit is certainly a sweet setup, but it’s more rifle than what most guys need. There is also some premium you’re paying just to have the same exact equipment that the special forces snipers are using, so it likely won’t give you the most bang for your buck. I’d suggest starting off with something like the Ruger Precision Rifle if you’re rifle budget is under $2k, or going with a full custom for around $5k. Both of those are way less than the Remington PSR, even if it was steeply discounted. I’m not saying it isn’t a great setup. It is. But it’s just way more than what most people need. It is cool to know that our troops are being supplied with such a great setup.
Thanks,
Cal
Cal:
For determining short range precision what is your predeffed magnification?
Thanks, Rick
We shot them all at 25x magnification at 100 yards.
Cal,
Great work as usual. Just an aside. I have been reading your blog for more than a year. Amazing the amount of information I have learned in that time. A thought struck me about this. Your blog is excellent +++. Are there any others on the web that you would recommend dealing with topics like precision shooting and/or reloading?
Thanks again.
Your,
Reg Curtis
Hey, Reg. Glad you’ve found this stuff helpful. There aren’t many websites out there with the same data-driven focus as mine, but here is a page where I provide a few links to other sites I’ve found interesting:
http://precisionrifleblog.com/links/
Thanks,
Cal
Hi Cal.
New to the site, but I’ve very much enjoyed reading your work. What sparked my desire to contact you is that Ruger recently announced their No. 1 single shot rifle in 6.5 Creedmoor and a 28″ barrel…
I’m curious, from your experience and research, have you seen many in the competitive world shooting rifles with less common actions like lever or single shot? Are there reasons they’re not popular?
Thanks, and keep up the great work. Can’t wait for your TBAC Ultra 7 article.
Hey, Keiichi. Lever action and single shot rifles certainly aren’t very popular in precision rifle competitions. Those kinds of competitions deal a lot with engaging multiple targets in a short amount of time, so single shot is just too slow. I was at a match this last weekend, and one of the guys in my squad had trouble with a magazine/action and it wouldn’t load rounds. He ended up shooting the rest of the match hand feeding one round at a time. Needless to say, he didn’t engage near as many targets as the rest of us. And a lot the shots are made from either prone or an improvised position. There may be times that lever action rifles were more convenient, but it would be the minority. Bolt actions have just become the standard for precision, and allow you to stay behind the rifle and cycle the action while laying in the prone position.
The single shot competitions rifles are probably more gear toward benchrest or maybe F-class. I’m not sure. I’m not in those worlds. I do know the benchrest world uses a lot of single shot actions. They are thought to be more rigid. But in the precision rifle competitions, having a repeater action that is magazine-fed is a must.
Hope this helps.
Thanks,
Cal
Cal:
Just finished studying the Houston Warehouse Experiment article for the 7th or 8th time. This time the remark about barrel length caught my attention. To wit, the most precision comes from 21.75 inch barrels for the rounds tested. Do you know what was meant by barrel length? The overall physical length of the barrel or something different? Secondly, has that observation ever been tested in a good experiment?At face value it is a very universal statement deserving rigorous verification.
Thanks, Rick
Great questions! I don’t have a clue. And with a measurement that precise, you even wonder what they were measuring from (i.e. total length including tenon, crown to bolt face, crown to front of lugs, etc.). There doesn’t seem to be a standard that everyone agrees on there. I typically talk about bolt face to crown, and think that is what the ATF definition is (relating to regulations around short barrel rifles).
I haven’t seen any experiments related to specific barrel lengths tested over multiple cartridges. I do think most 100/200 yard benchrest shooters use barrels that are 20-24″ long, with some believing 22″ being ideal. So it’s not a stretch to think they just experimented with lengths around that established norm of 22″ until they felt like they detected a pattern of the 21.75″ barrels being more precise on average than the others. But I don’t have a clue. It’d take a lot of barrels and ammo to be able to draw a statistically significant conclusion from, and that’s more work than I’m willing to volunteer for! For example that may be true for 6 PPC, but is it also true for a 338 Lapua? Is it true for all barrel contours? There are just a thousand permutations, so I think it’s unlikely there 21.75″ is some magically number that is the best for all combinations. That’s my theory at least!
Thanks,
Cal
Cal:
Thanks for your answer. Two approaches since it is the rifle-ammunition system assuming the external loading by the mechanical support and shooter are not significant. Same ammo and vary the barrel length or same barrel length and vary the ammo. A minimal brainer!
Upgrade CQI. Make it CPI, not consumer price index, but Continuous Precision Improvement.
Thanks and keep on shooting, Rick
HI. Have you ever tried a Victrix? then, perhaps, this article will modified 🙂
Hey, Giulio. I haven’t tried a Victrix. I’m guessing you think they’d compare favorably. 😉 I’ll have to check them out.
Thanks for sharing your thoughts!
Cal