Originally Posted by 308 nate
J E Custom . I am confused by your post as you do not address thread tenon diameter.are you saying that a 1/2 and 9/16 inch thread should never be used?It looks like your listing minimum muzzle diameter ,are you also saying that this would be your minimum minor thread pitch diameter? in fact 5/8x24 minor pitch diameter is .575 there for anything over.224 bullet diameter would be out.Could you clarify are you saying that you can install muzzle brakes on these diameter barrels, or are these dimensions referring to minor thread pitch diameter.if not what is the minimum thread diameter for caliber?
Yes you can use 1/2'' and 9/16" threads for brakes.
Example = If you have a .224 (223) you would need a .550 barrel diameter to install a 1/2'' 28
break. the minimum I listed was .563 to allow for poor threads or fit.
I use the Minor thread diameter because that is the actual wall thickness to the bore.
The number that engineers gave me was .140 thousandths absolute minimum wall thickness
for fluting at, or near the muzzle and muzzle brake threads Minor thread diameter should not be less.
If you do the numbers, most ARs are marginal with a 1/2x28 TPI thread. .224 bore diameter from
.4768 Minor thread diameter = .2528 divided by 2 you end up with a wall thickness of .1264,you end up with .013 thousandths less than the recomended .140.
This is the case where they are relying on the brake for some support .
The chart I use, takes in to account for as much as can be useful and allows for a fairly safe installation as long as the thread fit is very good.
The size of the thread and pitch is determined after the wall thickness is determined.
All Good questions , And I hope I answered them.
Remember these are my suggestions and if someone wants to deviate from It, That's fine.
J E CUSTOM