Let me describe my barrel:
The first 0.625" are threaded 1/2"x28 tpi.
The next 0.653" are 0.695" diameter.
The following length is 2.057" long and 0.730" in diameter.
We then step up to a section 1.916" long and 0.750" in diameter.
The next 0.765" are 0.850" in diameter.
From there we have an obvious 45 degree shoulder and the diameter steps up to 0.981" for the remainder of the barrel length. Save the last 2.500" which are a full 1.000" in diameter.
The reason I am asking is because I am considering purchasing the Ops Inc. flash suppressor and associated shoulder. If the numbers above are correct and the Ops gear fits, next Christmas Santa may bring me an Ops model twelve sound suppressor.
I just want to make sure the barrel dimensions are SPR profile for future use.
PS - Please don't gig my measurements - they were performed with a 35 year old Starrett slide calipers. I am not a machinist or an engineer but I did stay at a Holiday Inn Express last night.
SPR or not?