My son has the ridiculously large muzzle brake on his Ruger American Ranch in 7.62X39. This gun really didn't need a brake, but it has a threaded barrel and it is his rifle. I shot it once without hearing protection... My ears were ringing for two days... NEVER AGAIN!!!
Besides the increased auditory damage which muzzle brakes cause, most designs impart a concussive, sideways muzzle blast that you can actually see and feel on the firing line. This concussive blast, in turn, impairs to one degree or another the ability of fellow shooters on either side to accomplish any accuracy with their rifle.
Simply put, MBs are a range nuisance. ... And they're particularly a point of group aggravation at precision-rifle training events where you're actually trying to concentrate and absorb key elements of the precision skill-set, which concentration is being thoroughly disrupted shot-to-shot by
that guy (or
those guys) on the line with the most laterally concussive MB(s).
Last class I was attended, this training-impairment issue was remedied somewhat by herding the MB specialists and their shooting gear to the far end of the line, which also happened to be puddled and muddy from the previous night's rain. Serves 'em right.
Everyone else's learning curve discernibly improved thereafter.
Regardless of caliber, guys who install MBs on ARs - or precision bolt guns for that matter - seem to think they offer some 'tactical' benefit (they don't), or make their weapon easier to shoot (all shooting 'crutches' =
easier, not better), or perhaps help them identify - in a psychological way - with that 'Official Cool Guy' trainer-type whose YouTube vid about his really cool rifle they just watched the night before. ... Puleeese
Nope, when you sit down and objectively weigh the 'pros and cons' of MBs, ... - it's like, sorry, dudes, but you MB guys will be shooting
waaay down over there, at the wet and muddy end of the firing line.