A few years ago, I conducted a massive amount of primary research related to muzzle brakes (view results). I conducted several objective tests over a few months to quantify the performance of 20+ muzzle brakes designed for precision rifles in 6mm through 30 caliber. Very little objective research with controlled and repeatable experiments had been done on muzzle brakes up to that point. My goal was to equip fellow long-range shooters with as much hard data as I could reasonably gather to help them make an informed buying decision for their application. But, I was also trying to help manufacturers understand the importance of testing their designs and give them some insight into which features seemed to produce the best results.
The muzzle brake field test focused on quantifying the differences of the muzzle brakes in terms of performance in the areas that were most important to precision rifle shooters:
- Recoil reduction using a very high-speed compression sensor
- Ability to stay on target using lasers and high-speed cameras
- Noise level at the shooter’s position using a professional precision sound level meter that cost several thousand dollars
- Ground signature & muzzle blast using a very creative way to visualize how gas was directed
You can see the full results of that muzzle brake field test here, but the data from those tests clearly showed that the muzzle brakes from American Precision Arms were top performers across the board. I still have all of the muzzle brakes I used in that test, so I could obviously choose to run any of them on my rifles – but after analyzing all the data and getting hands-on experience with all the designs, I chose to run the APA Little B* Gen II muzzle brakes on my 6mm match rifles and I run APA Fat B* Gen II muzzle brakes on my magnum rifles, like my 300 Norma ELR match rifle. So that tells you what I think of APA brakes!
The only area where I saw room for improvement in APA’s design was when it came to helping you stay on target. The data showed that in that aspect they were good but not great. Many veteran shooters see staying on target as the most important features when it comes to a muzzle brake, even more than recoil reduction. Staying on target allows you to spot your own impact, which is the most important feedback you can have as a shooter. If you aren’t able to see your bullet splash you’re missing the most critical data you can have, and you’ll basically be sending the next shot blind and just hoping it connects. But, if you can stay on target and spot your own impact, you’d be able to see if you are slightly off the center of the target in one direction or another, and then apply a correction to center your next shot.
Through my research project, I got to know Jered Joplin, the owner of American Precision Arms, and I started hounding him to start offering top ports on his brakes. In fact, I considered taking the APA brakes I owned into a local machine shop to have a couple top ports drilled into them. But, as I learned through my testing, you can certainly overdo top ports. A couple of the muzzle designs redirected too much gas upward, causing the barrel to be forced downward, which can hurt more than it helps. The graphic below shows a glimpse of the results for my staying on target test. It marks the point where the rifle moved to under recoil relative to the point of aim, indicated by the red circle. I recorded this with a high-speed camera and then plotted how a laser moved in slow motion.
If too much gas is vented upward, it will result in downward force on the barrel, and essentially turns the barrel into a spring. The barrel will eventually rebound, and can cause you to lose the target as the sight picture bounces back up. Dr. Carlucci’s textbook on ballistics and design mentioned something similar: “If the weapon is already horizontal and the venting thrust has a large vertical component, this can be a substantial loading.” That is something that isn’t immediately evident, but should be kept in mind when designing and evaluating muzzle brakes.
You can see in the results above that a few of the designs also had slight lateral movement, meaning they didn’t track perfectly vertical and your sight picture would be thrown slightly off to the side after every shot.
Another tricky part of trying to quantify how well a muzzle brake helps you stay on target, is that the results can vary based on the cartridge and rifle you’re using. For my tests I was using a 6XC custom competition rifle, so the results are likely representative of a tactical precision rifle firing one of the mid-sized cartridges that are popular in PRS competitions. However, if you are using a big magnum or a hunting rifle where the weight is distributed differently, the amount of gas you need to vent upward to offset muzzle rise could be very different. It could theoretically vary based on the bullet weight and powder type that you are using on the same rifle! How much gas needs to be directed upward is a dynamic problem and the right balance on one rifle setup may not be the right balance on another. For example, you can see in my test results the JP Tank was virtually perfect for my test rifle, staying right on top of the point of aim – but it’s very unlikely that same brake would be perfect for other types of rifles.
However, all of that didn’t prevent me from nagging Jered on multiple occasions to start offering a brake with top ports! Jered told me a couple times they were working on a new design with top ports, but they wanted it to be perfect and went through testing on a few iterations and prototypes. Fine! I can appreciate a thorough R&D process. 😉
Just a couple weeks ago, APA released the brand new Gen III Little B* Muzzle Brakes, and I can honestly say what the team at American Precision Arms came out with was far more clever than what I’d imagined. Here’s a look at how the Gen III design compared to the previous Gen II design:
The Gen III Little B* muzzle brake design is similar to another brake APA released a few months earlier called The Answer, which is designed for AR-15 platforms chambered in calibers like 223/5.56 and available in thread patterns like 1/2×28. However, the APA Gen III Little B* muzzle brake is designed for precision rifles and is currently available in 6mm, 6.5mm & 30 caliber with a 5/8×24 thread pattern, with more variations to come in the near future.
3 Key Improvements on the Gen III Little B*
- Tunable top ports allow shooter to fine-tune muzzle movement for absolute target retention
- Addition of a 4th port that eliminates even more recoil than before
- New lock nut design prevents brake from rotating as you tighten it down
Unique Recoil Profile (URP) Tunable Top Ports
APA is calling these “Unique Recoil Profile” top ports, because of the reasons I mentioned earlier related to every cartridge and rifle configuration potentially have a different sweet spot for how much gas needs to be redirected vertically or even laterally to keep your sights on target through recoil. Tunable ports are an elegant solution to that problem. APA says these “allow the shooter to not only combat direct recoil but muzzle rise and lateral movement based on the characteristics of their rifle, personal grip, stance and the position they are shooting from.” There are 8 tunable ports total, and each has a threaded plug that you can remove to tune how much gas is redirected both vertically and to the sides.
APA says when they developed the URP adjustable gas system, they didn’t just randomly place the top ports. They explain that “every port is placed adjacent to the internal Bastard tooth where there is maximum pressure build-up. This makes the adjustable ports directionally effective.”
One of the more technical concepts related to this is the amount of pressure at each baffle is slightly different. Simulations show pressure is highest at the first port, and some amount of pressure bleeds off with each subsequent port. So if you remove the set of plugs at the first baffle (near #1 in figure below), it will redirect more gas upward than if you removed the plugs at the last baffle (near #4 in the figure below). Said another way, the ports closer to the nut have a more dramatic effect and the ports closer to the crown have a lesser effect.
So, if you notice as your rifle recoils that your sight picture goes up and slightly to the right. You might try removing the two plugs near the first port, and one of the plugs on the 4th port on the right side. If you remove a screw on the right side, it will shift the rifle left and vice versa. If you try it with that configuration and notice your sight picture is still going up, remove more ports so more gas is vented upward. If the sight picture is going down, try plugging the first set of holes and removing the second set of plugs. With eight total plugs, there are 256 possible configurations and you should be able to find the perfect balance that provides a truly neutral sight picture for your unique recoil profile.
Addition of 4th Set of Ports
The original APA Little B* muzzle brake design had 3 ports on each side, but the Gen III design adds a 4th set of ports and is only 0.325” longer! That is less than 3/8 of an inch of added length and just 0.3 ounces in weight, which are both negligible compared to the potential benefit. In my research, the original 3 port design reduced recoil by over 40%, which was one of the absolute best performers and a full 10% more than the average brake. The 4th port would only help to further reduce recoil.
Unfortunately, I’ve sold my test equipment and can’t quantify how much of a further reduction in recoil the 4th set of ports adds. It likely depends on the amount of gun powder you’re burning, and based on my experience testing, I’d suspect it may be insignificant for smaller cases like the Dasher and BR-based cases, but it would likely be a noticeable decrease in recoil on larger cases, especially magnums.
New Lock Nut Design
APA’s Gen II design was the first to feature an integral locking nut design, which meant you didn’t need a gunsmith to “time” the muzzle brake to your barrel. “Timing” simply means that when you tighten the muzzle brake onto your barrel, the ports are facing the right direction. A gunsmith shaves off a tiny amount of material off the brake until it is right for the barrel. That’s a pain in the butt, especially if you’re one of the competitors that goes through 8+ barrels a year. APA’s locking nut design allows you to spin on the muzzle brake, get the ports pointed in the right direction, and then just tighten the locking nut to keep it in place. The APA locking nut gives a much more polished look than crush washers or spacers, and it’s an elegant solution … that a lot of other manufacturers have
copied been inspired by. 😉
But, one inconvenience with the Gen II locking nut design is that when you are tightening it down, the brake would inevitably rotate very slightly and sometimes meant the ports were no longer pointing at a 90 degree angle to the ground. So you’d have to loosen the nut, realign the brake and try again. It typically would take me 2-3 tries before I got it right. It’s not like you take the muzzle brake off all the time, so this was only minor annoyance for me.
Area 419’s Hellfire Muzzle Brake, another very popular muzzle brake among precision rifle shooters, fixed this issue through the use of an adapter and clever collar/cone design that prevented the hassle of over-rotating the brake when installing it.
So for the Gen III design, APA modified their brake to prevent the over-rotation issue, in hopes that you get the perfect muzzle placement the first time. APA says the new locking nut design also provides an even stronger lock-up, and the design also prevents the accuracy-robbing carbon ring that is common on other platforms.
I’m clearly excited about this new Gen III muzzle brake design from APA! Jered Joplin and his team are an innovative group that are industry leaders when it comes to brakes. But, as always – this isn’t a paid advertisement. APA didn’t ask me to write this post. I simply believe a muzzle brake is an often under-appreciated but critically important part of a rifle, and this new design offers innovative features – especially when it comes to helping you stay on target. So while I may sound like a fan-boy, I just wanted to try to get the word out to ensure my readers were aware of this new product, which seems to be more than just an incremental improvement over other designs. If you want the bottom line from my perspective, I’ve already switched my personal match rifles over to these and have certainly enjoyed using them!