This chart is a listing of dimensions



However these are shotgun cartridge dimensions. It is not a 24 gauge

A couple of pictures with all proof marks and barrel stampings would help.

Also a chamber casting in order to get chamber dimensions. Further slugging the barrel to get clear bore with lands and grooves dimensions would be good.

There are a number of European cartridges with approximately 9mm bores

it is not likely to get an answer with the data you have provided so far

Last edited by old colonel; 03/01/17 10:31 PM.
Michael Dittamo
Topeka, KS