I  have a ASA 9MM upper.  Mine is a post ban so there is no flash hider or baynoet lug.  However, since the ban has expired I have been considering having the barrel threaded.  Therein lies my question(s).

Do they use the same flash hider as on the 223? Assuming it is bored out to accept the 9MM.

Are the barrel threads the same as the 223,  1/2" x 28tpi?

What is the wall thickness of the 9MM barrel at the threads?

I have a 9 MM surpressor (registered!) that I'd like to use on it but it has 1/2" X 28 threads.  I'm concerned about the wall thickness of the 9 MM threaded barrel.  I'm told it will finish out at 0.075".  I mic'd a 9MM pistol barrel that only mic'd 0.050" but would like some reassurance that this would not damage the barrel.  Any facts and/or opnion you could share would be appreciated.

Colt 9mm's are usually 1/2 x 36 dpi.  The 9mm FHs and 7.62x39 FHs are the same.  I don't see why you can't thread yours for 1/2 x 28.  If you decide to go with a different thread pitch, you can always get a thread adaptor from TROS to go from pretty much anything to pretty much anything else (probably about $60).

Thanks for the reply and the offer, however I have a local source that is capable and willing to do the work.  He was the one that called my attention to the 'finished' wall thickness and wanted confirmation before proceeding.  I was going to check with ASA but they seem to have disappeared!