Perfect, thanks Gunny. I am contemplating running a .22 STX on my .23" ported valve and needed that OD, still tossing around the idea but having that dimension greatly helps design it on paper before I execute!
Very odd dimension though, would need to turn it down to .3125" or 8mm, and sleeve the barrel to fit my receiver, which would have a thimble built inside of the sleeve to accommodate a transfer port...but being ported over bore I may want to wait and see how their slug liners perform before I do any serious considering.
-Matt