Something like this (which per the ad is local to the OP down under in NSW) might be the ticket for punching one's own: https://www.ebay.com/itm/17mm-Boker-Wad-Punch-Made-In-Germany/263214003461?hash=item3d48c6f505:g:pRMAAOSwQTNZtfvM
On a lot of French and Belgian 16ga guns, the bore diameter will be stamped as 17.0 (or 16.9), the measurement in millimeters.


fiery, dependable, occasionally transcendent