At media range day, I headed over to CMMG to see what all the noise was about. I had been shooting a few bays over, when some very loud automatic fire caught my attention. It was the 10″ barreled Mutant (MK47 K), their AK-47 magazine compatible rifle, with a 10″ upper and their .30cal SV brake, as well as as an upper that had their new Krinkov-style brake attached. After a break for setting up targets and oiling the bolts (they had been fired constantly for 2 hours at that point), It was my turn to have a go.
The 10″ barrel with the SV brake was easy to keep on target, and had very little muzzle rise, but was teeth-rattlingly loud! We were in an open bay with no roof, in broad daylight, and I could see plenty of flash in my peripheral vision as well. Recoil and muzzle rise were duly tamed, however. Then, I tried the Krinkov-equipped upper for comparison, and it was a different story. The Krinkov brake made the rifle more muzzle-heavy. Felt recoil and muzzle rise/control were worse than with the SV brake, yet all the blast and most of the sound were sent forward away from the shooter, making for less auditory disturbance. Overall, both uppers ran fine for having so many rounds put through them in full auto, and the new brake gives end-users more options to choose from.