I have no experience installing or using muzzle breaks. I haven't had the need to use them. I've decided to extend a T/C Contender .30-30 14.5" barrel to 16.25" so it can be used as a carbine. The barrel was threaded concentric to the bore and an extension made which is also concentric to the bore. The muzzle was crowned with a flat recessed crown and the extension seats snug to the muzzle. This will be used mostly with cast bullets. What clearance is generally accepted as right? I was thinking the extension should be bored to about .330. I'm not concerned with a bullet hitting the inside of the extension. I was thinking more about gas or lube affecting accuracy. Would it be better if the inside of the extension were opened with an expansion chamber? What do you guys think? Thanks.
