I recently had a custom rifle built that was chambered as a 7mm Remington Magnum. I plan to use it as a dual-purpose rifle:
- Precision rifle matches (target shooting out to 1000 yards)
- Hunting (primarily whitetail & mule deer and the occasional wild hog)
I did a ridiculous, almost embarrassing amount of research before landing on the 7mm Rem Mag cartridge. After losing a deer last year, I wanted to make sure it had enough energy to put an animal down quickly. There is no such thing as overkill. With that mindset, I actually started by looking at the 300 Win Mag, and after pouring over ballistic tables I started thinking about a 7mm STW or even a 300 Win Mag necked down to a 7mm (like the 7mm Practical) instead. To get a high BC bullet in 30 caliber you need to go up to a 200gr bullet … which is way heavier than I needed for hunting, and you have to put a lot of gun powder behind that to get the same ballistics you can with a 7mm. All of that adds up to a lot more recoil, and I didn’t want to develop a flinch. There are a ton of great, high BC bullets offered in 7mm that were closer to the optimal bullet weight for the game I had in mind. The thinner diameter of the bullets (7.0mm vs. 7.62mm for the 30 caliber) seems to naturally lead to more aerodynamic bullet design. Here are a few specific bullets I thought might work:
|Bullet||G7 BC*||G1 BC*|
|Berger 168gr VLD||0.316||0.617|
|Berger 180gr VLD||0.337||0.659|
|Hornady 162gr A-Max||0.307||0.599|
|Cauterucio 177gr VLD||0.349||0.683|
*All BCs are from Applied Ballistics for Long-Range Shooting by Brian Litz (2nd Edition)
I selected Clayton Smith with West Texas Ordnance as my gunsmith, and here are the specs of what we ended up building:
|Action||Stiller Predator Long Action Stainless (.534” bolt face, .300” tapered recoil lug) with Stiller 30 MOA forward cant 1913 picatinny rail, fluted bolt, and oversized tactical-style bolt knob. Stiller Precision Firearms manufactures custom bolt action recievers using the latest CNC technology. They are a primary supplier for many OEM manufacturers including Les Baer, Gunwerks, and the U.S. Miliary. The Predator action is a drop-in replacement for the Remington 700, so it can fit in any stock the Remington 700 can. The top is full round and uses two front bases rather then the stepped down one on the rear of a Remington. This allows for better scope alignment. The magazine-fed actions use a 0.15″ extended cutout to allow for longer cartridges and H-S Precision or Wyatt boxes. The port has been opened a little for the same reasons. The bolt is a little looser than benchrest actions to avoid problems with grit and particles. It has 0.004″ clearance, which is much less than a Remington, but a little more than BR actions. Jerry Stiller says: “If you are going out to buy a Remington donor rifle, STOP, give us a call. The Predator may cost less by the time that Rem action is trued and blue-printed.”|
|Barrel||27″ Krieger fluted stainless steel cut-rifle barrel in #19 hunter contour with 1:9 twist. There are lots of good custom barrel makers out there, but I went with Krieger because they use a single-point, cut-rifling process. Although this process is significantly slow than button-rifling (and therefore more expensive), it produces almost perfect concentricity between the bore and groove, a very uniform twist rate, and introduces no stress into the steel. I went with a 27″ barrel to give me plenty of room to set the barrel back an inch and re-chamber after the throat starts to erode. Even after the set-back, I’ll still have a 26″ barrel, which should still give me the velocities I’m looking for. According to Berger’s new reloading manual, you can expect the 7mm Rem Mag to have 31 fps difference per inch of barrel.|
|Trigger||Timney #510 adjustable from 1.5 to 4 lbs. Mine is set to 1.9 lbs. I thought about going with a Jewel, but the Timney has less open ports on the bottom of it that sand and grime can get into. Since I will be using this in very sandy conditions in the field, I didn’t want to introduce a chance of trigger failure. Timney triggers are built to tolerances less than .0005”, and are made from a solid block of heat treated steel so there’s no “connector bar” to come loose. The 510 also comes with a safety that blocks the trigger, not the sear. That means there’s no way to move the trigger when it’s on safe, and when you take it off safe the trigger stays in the exact same position.|
|Bottom Metal||Wyatt’s Outdoor long action detachable box magazine (DBM) system with 5 round & 10 round magazines. This setup gave me a tenth of an inch more clearance than the AI mags would have. Wyatt’s Outdoor magazines aren’t any cheaper than AI magazines, but the build quality is in the same class.|
|Stock||McMillan Adjustable A3-5 in Desert Camo with integral cheekpiece adjustments, spacer system for adjustable length of pull, 2 flush cups, 1 forend stud for a bipod. This is a combination of McMillan’s A5 and A3 stocks. The A5 is the bestselling stock to civilians and has a lot of great new features (see diagram below). The A3 is “the most widely used field sniper stock available”, and is made to be less bulky and lighter weight for field use. The A3-5 is a hybrid between the two. It essentially brings in all the new features of the A5 (like the butt hook, which is great when using a rear bag), but maintains the more streamlined profile of the A3 so it is easier to maneuver in the field … and it shaves a full pound of weight off the A5.|
|Finish||Cerakote in Coyote Tan – Cerakote is an extremely durable, weather- and corrosion-proof, ceramic-based protective finish that resists scratching, chipping, and abrasive cleaning solvents. It is spray-on and ovencured. Hardener and paint chemically bond into an ultra-thin coating that adheres to almost any surface for a clean, professional finish. There are similar products out there, but none compare to the how tough Cerakote is. To see the difference, the results from a labrotory abrasion test for several popular types of firearms coatings is provided below. To see more test results, visit http://www.cerakoteguncoatings.com/testing/.|
|Muzzle Brake||OPS Inc R3E2C muzzle brake, 5/8-24TPI thread with interchangeable thread protector/barrel cap. I was considering a Holland brake, but went with the OPS so I could keep a more standard barrel thread pattern. I plan to add a suppressor at some point, and didn’t want to have to add some type of custom adapter. OPS is the exclusive supplier to U.S. elite forces. Originally developed for the military, the OPS Muzzle Brake is the result of extensive research into muzzle gases and the effects of redirecting them for recoil reduction and accuracy enhancement. A single, large expansion chamber followed by a baffle traps redirects gases 90 degrees from the barrel to eliminate dust printing, muzzle rise, and back blast. This design also eliminates a great deal of the sound that would be directed back towards the shooter with traditional muzzle brakes (although it is still loud). OPS claims recoil reduction of up to 70% with virtually no “puff” back at the shooter. I’ve now shot it with and without the muzzle brake and it feels like it reduces the recoil 30-40% on my rifle. Don’t want to take my word of it, check out their stellar reviews on Brownell’s.|
|Scope||Nightforce NXS 5.5-22×50 with ZeroStop & MOAR Reticle – I love this scope for its ruggedness, high quality glass, broad magnification range, high-speed turrets, 4″ eye releif, and 100 MOA of elevation travel. Combined with the 30 MOA of cant from my rail, this gives me 76 MOA of drop adjustment in my scope which means I have more than enough to push beyond 1 mile without having to “hold” for drop … yet even when I’m shooting at 100 yards I’m still within the “sweet spot of the scope” (i.e. not on the extreme edges of elevation adjustment, which Bryan Litz says can impact accuracy). The “high-speed turrets” provide 20 MOA of adjustment per revolution which is more than most scopes, so it takes less full revolutions to get to my adjustment. The ZeroStop option is also amazing for tactical or hunting situations, and well worth the extra money. Overall the Nightforce scopes are just a great bang for the buck. I was considering the Schmidt & Bender 5-25×56 PM II/LP/MTC/LT, but the price is twice as much ($4k instead of $2k) and ultimately it’s not twice as good of a scope. But, the #1 reason I went with overall the ridiculous durability and ruggedness. To show the extent to which this is true, read this story about a U.S. soldier’s Nightforce scope that was shot straight through and continued to function.|
|Scope Mount||Spuhr Ideal Scope Mount SP-3001 – You may not have heard of this mount (yet), but it’s amazing and honestly lives up to it’s name … it is completely ideal. The engineering and thought behind this mount puts it in a class of it’s own. My favorite features are the 45 degree split ring design which is ultra-compact, and allows you to see your turret adjustments with minimal head movement. The included wedge is brilliant for quickly leveling your scope in the mount, and a bubble level is conveniently built into the rear of the mount and therefore always protected and never at risk of being broken off or accidently re-adjusted in any way. It also provides 8 interface points where virtually any accessory can be attached without the weight and added bulk of having 3 feet of picatinny rail all over the mount. The built-in attachment points allow the user to mount a variety of interfaces for reflex sights, nightvision equipment, thermal attachments, lasers, illuminators, cosine indicators, picatinny rails, etc. There are really no limitations to what can be attached. I went with a model with no built-in cant, because my rail already had 30 MOA of cant built into it. I think this makes hte mount more flexible, because I could move it rifle to rifle if needed as long as each rifle had the appropriate amount of cant for that specific cartridge built into the rail. For example, I’d probably want a rail with 43 MOA of cant for a 338 Lapua and by putting the cant into the rail it is specific to the gun … but a 0 cant scope mount isn’t specific to any gun.|
It ended up weighing in at 11 lbs 4 oz before optics, and is 51 3/4″ long with all of the length of pull spacers on the stock and the muzzle brake attached. Fully loaded it weighs 15 lbs 0.2 oz, which includes 5 rounds, Harris 6-9″ bipod, scope & mount. (Update 6/19/2013: After carrying it at many matches (including the Steel Safari where you had to hike miles in rugged terrain for 3 days straight), I am still totally comfortable with the weight of the rifle. It is heavier than a sporter, but I actually think I could take slightly more weight without it becoming a real problem. The right weight is subjective, but to me this is a great balance of portability and accuracy.)
With less than 100 rounds down the barrel, I’m already ecstatic about the accuracy of this rifle. My FIRST 3 shot group with match grade handloads had an extreme spread of 0.188″ … that is ridiculously good any rifle, but even more so for a non-benchrest rifle under 15 lbs.
I ended up taking it to a precision rifle match this past weekend, although I had only fired 50 rounds out of it (and none past 100 yards). I had fired over a chronograph and done a quick Audette Ladder Test to get a rough idea for a potentially accurate handload for Berger 168gr VLD, and plugged my muzzle velocity and Litz’s G7 BC into JBM’s ballistic calculator to work up some completely theroetical dope. To my surprise, I had amazing results. The competition had 36 targets mostly from 300-650 yards, and you were only allowed to fire one round at each target (no sighters). I ended up hitting 29 targets in a row before my first miss. I couldn’t be more pleased with the rifle.
Update 12/28/2012 – I’ve stretched this rifle out to some pretty far distances while target shooting. IPSC sized targets are a chip shot at 1000 yards, and I can still get 50% hits at 1,400 yards. We also set up a 1 mile target a couple weeks ago at the range where I shoot, and with the help of this rifle I became the inaugural member of the 1 mile hit club (witnesses present).