All of our muzzles are threaded concentric to the bore line at the muzzle end and are test fit to a class 3 ring gauge. This guarantees that any standard muzzle device or suppressor you purchase will thread right on. The price on all muzzle threading is $110 plus return shipping and in some cases there may be a disassembly/reassembly fee. This price is for threading only and does not include a muzzle device or thread protector.