How much seating shoulder for a suppressor?

[PrairieGhost]

I have never run into a questionable barrel before so I'm looking for your thoughts.

A couple weeks ago I purchased a Sig model 320 Xvtac. My suppressor was in the mail and on te way so I ordered a 5.5 inch threaded Sig barrel. It didn't want to seat firmly and tightened beyond the shoulder. Here is the problem I think I have. This barrel has two shoulders when I think it shoukd have one. The thread is 1/2 x 28. The thread diameter is .499 inch. the shoulder diameter is .511 inch. The opening before the threading in my suppressor is .506 inch. So the diameter of the barrel at the shoulder is only .005 inch larger than the opening to my suppressor. That's diameter so I actually only have .0025 inch all the way around to seat against. Am I being to concerned?

[SupressYourself]

That would concern me as well. Not sure why there's not a single shoulder there. I would reach out to Sig and see what they say. Maybe there's some kind of "washer" or something you can use.

[sweeney]

Or contact your suppressor company with the same picture and info.

[Ruddy Duck]

Check with your suppressor company. My pistol suppressor on my ar9 has no shoulder and they said it's fine-said not to add a washer or spacer.

[PrairieGhost]

Check with your suppressor company. My pistol suppressor on my ar9 has no shoulder and they said it's fine-said not to add a washer or spacer.

What do you do then, just screw it on until the threads run out? How does it seat so it doesn't unscrew or have movement?

[Ruddy Duck]

Just thread it on as far as I can and check it every few magazines. Haven't shot it a ton but no issues when i have.