It varies, latest is 1/2"-28tpi. Best way to be sure is measure it on your particular gun after you remove the FH. A 1/2" socket drive Torx T-60 bit fits into the front opening of the FH
Mine is 1/2 x 28.
I believe after 2010 they were 1/2 x 28. You could call ruger and I'm sure they could tell you for sure.
Originally Posted By bw77:
Mine is 1/2 x 28.
I believe after 2010 they were 1/2 x 28. You could call ruger and I'm sure they could tell you for sure.
All of the new flash hiders use the standard 1/2 x 28 pitch. I made 700 last week.