I have a question? I noticed that on brownells website on the muzzle threading bits that there is different , I am guessing thread angles ( square, 55 degree, 60 degree). What the different degree's for? Does it matter what's used? I never noticed when ordering a muzzle brake, ect they never say. If you have a threaded muzzle with a 55degree can a threaded brake with a square thread be used?