So I ordered at TBAC SR brake for my .308 barrel and I have been trying to figure out if TBAC SR Brakes are all the same with just a different threads to match different barrels or if they are actually bored for different calibers. Further more are there different revision of them since it seems like some have 4 small holes on the top of the brake but others don't. Is the SR Flash Hider available and Is it caliber specific or just one size fits all? Any third party companies coming out with a compatible muzzle device? Thanks in advance.