how much threading

[liljohn]

How much threading is at the end of the barrel? I have an unthreaded barrel I need to have cut and the gunsmith wanted to know how much to put on. Thanks for any help.

 

[M1ASupermatch]

While installing a new flash suppressor on my M&P 10 I had to use three crush washers to fill the extra space left by the stock supressor. I would recommend threading the barrel no more than the depth of the treads of the muzzle device you plan on installing.

 

[HDDP]

.625" on mine.

 

[liljohn]

Thanks, that's what my ar15 measures as well.