The Precision Armament M-11 Severe Duty, AR muzzle brake takes the traditional side venting, approach to the problem of recoil reduction and add a twist: two large upper ports. It’s a small work of art, also reminds me of the wheels located on WWII era German panzers. This is a brake which you have to hold on your hands to fully appreciate. Aside from the quality of the machining, possibly its top condition is the beautiful aerodynamic lines along with its silky smooth satin polished feel. But there’s more to the M-11 than just good looks. The brake is made of heat treated pressure relieved 400 Series Stainless Steel.
This material retains great dimensional stability throughout the cutting process, and a lot more corrosion and erosion resistance which standard chrome moly steel. The brake can be finished in state-of-the artwork Diamond Like Carbon at a low luster Matt Black. The brake’s massive blast deflectors make three different blast chambers. The first chamber is the biggest, and each one of the two chambers decrease in proportion. The last two blast chambers also include large vents to keep the muzzle down at the top of the brake, so that gas is directed upwards to keep the muzzle down. TTAG author Jeremy S. Seized this Amazing money shot of the M-11 in the blast.
The blast baffles are only angled so slightly in the back. In this regard, Precision Armament is making a deliberate effort to equilibrium recoil reduction against the adverse effects associated with rearward led noise and concussive force. Consequently, this brake is loud, but not as loud as other brakes I’ve used. The M-11 is a non-symmetrical brake, and, as a result, has to be suitably timed, or glued. , Traditionally, muzzle brake designers have taken two approaches to this problem. Companies like Grizzly Gunworks utilize an allen screw clamp system to index their threaded brakes. While that system has the advantage of being easy to remove for cleaning, it does increase bulk, weight, and theoretically might get stripped out.
Precision Armament wanted to keep the svelte aesthetics to the M-11, so it chose to utilize a pair of custom sizing washers. Notably, Precision Armament doesn’t recommend the usage of crush washers, due to the inherent possibility of misalignment. In place of crush washers, Precision Armament designed the proprietary Accu Washer, Muzzle Alignment System. The pair consists of a series of 18 independently marked appliances, all of a somewhat different width. Employing these washers, the timing is adjustable from 0-360 degrees in 20 deg increments. The tools are precision machined from high strength 400 series stainless sheets of steel to guaranteed thickness uniformity of ±, 0.0001.
The exact tolerances of those washers ensure the most accurate alignment of the bore is possible. Since only one Accu Washer is necessary for every rifle, the system avoids cumulative effects, a problem that’s frequently associated with peel washers along with other multi shim systems. It took me about an hour of sorting and trial and error fitting to get the timing right on my Savage Model 10 TR, however, that I have the correct washer chosen, I will remove and reinstall the brake at less than a minute. The Accu Washers work nicely, but some folks won’t like that the washer stays visible once installed.
The M-11 is threaded for 5/8 – 24 threads and can be produced to match one of the four bolt diameters: 6.5 mm, 6.8 mm, 7.62 mm, and 8.6 mm. This is my summary of the benefits and drawbacks of the M-11: Benefits! Good dust suppression for prone shooting. Doesn’t display a tendency to loosen. Excellent reduction. Comparatively easy to clean due to big baffles. Disadvantages: the First-time install is time consuming due to the timing, issue. Louder than M-41.