Ask Foghorn: Best Muzzle Brakes/Compensators for the AR-15

Reader Don writes:

I really enjoy reading your reviews and you actually inspired me to try a 3 gun competition at my local range. Even after negotiating through my California bullet button and 10 round mags on my AR, I still have a blast and plan to compete again this month. At the competition, each paper target required two shots. One thing that was obvious is that many guys were able to get that second shot off much faster than I was. Initially I attributed to me having iron (actually plastic magpul) sights on my AR while most of them had red dots. After talking to the other shooters and and them observing them shooting, it looks like the muzzle breaks make a big difference as well (my AR has the stock A2 flash hider). There were a variety of different breaks in use from sure fire to battle comp 1.0. I was looking through your past articles and was not able to come up with much info on muzzle breaks. Could you provide some information and/or suggestions on muzzle breaks? They appear to be expensive (compared to an A2 flash hider) so I wanted to see what others experiences are before I went all in.

It’s definitely the brake and not the sights. People might bash irons, but they’re damn quick if you’ve practiced with them. Let me share with you what I’ve learned . . .

When I first put a compensator on my competition AR-15, my teammates laughed at me for being a pansy. Something about how I needed some help with the “punishing recoil” of the 5.56 cartridge. But when I consistently beat them in competition after competition, they changed their tune and joined in.

When a gun goes off, what’s really happening is that a small cache of powder is burning in your chamber and creating gasses that propel a projectile down the barrel. When the projectile leaves the muzzle, these gasses escape and are turned into noise — the report of the firearm. Those expanding gasses, in addition to the projectile, create a sizable impulse rearward, as Newton’s laws of physics need to be satisfied with the conservation of mass and momentum (equal and opposite reaction and all that). That’s the recoil we feel. And the more mass, the harder the recoil.

A muzzle brake or compensator is a device attached to the end of your rifle that uses the excess gasses from the round going off to create a force that counteracts the recoil of the gun. It does this by redirecting the gasses as they leave the barrel and having them apply some forward force to the baffles of the brake. The net effect of the muzzle brake is that the felt recoil of the gun is reduced.

Recoil reduction isn’t the only thing that a brake does, though. With most modern guns, there is a significant amount of upward movement of the muzzle in addition to the rearwards recoil. Muzzle brakes compensate for that muzzle climb as well. Some even compensate for the rotational force applied by the spinning bullet in the barrel.

The general rule of thumb for muzzle brakes is the bigger and more aggressive the brake, the more recoil is mitigated. Like this gigantic one here. The idea is that the more surface area there is for the escaping gas to contact, the more recoil reduction there will be.

But bigger isn’t always better, for two big reasons.

First, bigger muzzle brakes and compensators make the gun much louder for those standing nearby. I’ve had more than one person complain about my competition rifle with muzzle brake while on the firing line, even when larger caliber rifles are only a few steps away. For someone who enjoys their quiet firearms these days, a compensator can be a little annoying. And bigger ones are almost always louder.

Second is that big muzzle brakes aren’t necessarily “legal” for competition shooting. For 3-gun, most divisions limit you to a 1 inch by 3 inch muzzle brake at the absolute maximum, and larger ones (silencers are included here) kick you into open division. It keeps the competition fair, limiting the help you get from muzzle devices.

So, what is best in muzzle brakes?

Silencers, believe it or not, are fantastic muzzle brakes. Go figure that the same mechanics that trap the gasses and quiet down your gun also reduce recoil. But they’re not competition legal for most cases, and include a $200 stamp and some paperwork.

My favorite muzzle brake of all time is one I had on my rifle for a while: the PRI MSTN QC Brake.

This brake, available in stainless and black finish, uses three chambers to redirect the gasses and counteract the PUNISHING RECOIL of the 5.56 cartridge. Its competition legal, does a fantastic job, and is usually in stock (unlike the similar JP Enterprises brake which is (A) a little flashy, (B) lacks a chamber and (C) a little flashy).

However, if you’re a gigantic nerd like me and want to fine tune your compensator to exactly match your gun’s recoil, then the Ares Armor Effin A compensator is what you need. Available for .308 and 5.56, this device will allow you to fine tune the way the gasses are redirected, and if you love tinkering with stuff this is right up your alley.

In the end, it comes down to personal preference. I really like the PRI MSTN QC brake, and so do all of my friends who have tried it (and still use it on their competition guns), but there are other options, and by no means have I tried them all. If you find one that you like, go for it and be happy.

And a word of advice: double check that you get it in the right thread pitch for your barrel.

[Email your firearms-related questions to “Ask Foghorn” via guntruth@me.com. Click here to browse previous posts]