We do a 13x1 in our over barrel suppressors, flick me an email. sales@dpt.co.nz
Type: Posts; User: DPT
We do a 13x1 in our over barrel suppressors, flick me an email. sales@dpt.co.nz
1mm pitch is 12.7 threads per 12.7mm length, so I think you are pretty spot on for 13x1
Looks too fine for 1/2-20 and if those calipers are correct then its more than likely 13x1