Thread: Muzzle brakes - Overbore Efficiency

The closer the hole in the brake is to bore size, the greater the performance. Brakes are best at about 0.5 - 0.6mm (.020 - .025") over bore size but must be accurately fitted in true alignment. Having said that, you will find they still work reasonably well at 1.00mm over (0.40"). The number of impingement faces (chambers) is probably more important but there are diminishing returns as the number increases, 3 is about minimum and 5 about maximum.

Originally Posted by gundoc

The closer the hole in the brake is to bore size, the greater the performance. Brakes are best at about 0.5 - 0.6mm (.020 - .025") over bore size but must be accurately fitted in true alignment. Having said that, you will find they still work reasonably well at 1.00mm over (0.40"). The number of impingement faces (chambers) is probably more important but there are diminishing returns as the number increases, 3 is about minimum and 5 about maximum.

Good to know the new ones bore is .344ish so would be 0.060" might be pushing things a bit