Re: Muzzle brake opening?
Mach V, I've seen .020" clearance on the radius, or .040" on the diameter. That would make the exit hole .348" internal diameter. Screech has the right idea, though. .338" on the diameter should make the brake more effective. .375"+ sounds too big for a .30 cal, and if I understand brakes, would make it less effective, but might improve accuracy for that particular rifle. Minor changes in muzzle geometry or mass can make major changes in accuracy.
I don't like brakes, but have 2 rifles that have them. One is a custom, the other is a factory brake. The custom .338 cal exit hole is .378". The factory .458 cal exit hole is .500".
Just had a thought; maybe the brake was sized for a .338 cal.
Good shooting, Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time