Okay, quick update, I just fished out some old unfired 20 Gauge Remington Kleenbore shells from the sixties and they do chamber...but are tight (I need to pop them out. So i obviously have a 20 and not a 24. I'll send the barrels off to Michael Orlen this week to have the chambers sorted out (without lengthening them). Sorry for the false alarm and hopefully Old Colonel has not yet mailed me 2 24 gauge shells. Many thanks to all.

Joe U