I've been away, just got your messages. I live in Alaska, I can only guess that the muzzle brake
dose effect the velocity but I'm sure by very little. Muzzle is .665 or 21/32. Barrel length is 26".
There is an up date on this gun-I have tested it for velocity's and groups and so far I'm quite pleased with it! I've barley broken in the barrel and I'm getting an average velocity of right at 2700fps with 300 burgers. The most impressive news is, I'm getting groups of less than 3/4.
Because of performance I'm really tossed about selling it at this point?