Rifle Thread

[Kiwi Greg]

Pitch seems to be 24 threads per inch, so my guess is either 1/2x24 (standard on .22LR, and my old gunworks .308 suppressor) or 3/8x24 (standard on .308 AR10's etc).
Get a photo taken of the crown of the barrel to determine which it is.

1/2 x 20 is the standard 22LR thread, 5/8 x 24 is the standard AR10 thread

By the look of the pics it could well be 9/16 x 18, but its difficult without the diameter

1/2 x 20 is a little average on a 308 muzzle to be fair

[gadgetman]

1/2 x 20 is a little average on a 308 muzzle to be fair

It's what they put on mine. Wasn't a great deal of meat to go any bigger, but could have gone for a finer thread.