No worries, mate, no feelings hurt here.
I'm just happy that there is at least one aspect of the shooting sports that is attempting to remain 'pure' insofar as the gun types allowed. Remember - the premise of the event is the movie. throwing it wide open, you'd have to call it something else.
I've got a Mossberg 590A1 and my wife has a Rem Tactical 20 ga we use in Modern 3-Gun. I'm quite happy NOT to see such guns in a CAS event. Cheap way in for a shotgun is to buy a Norinco and beat the hell out of it!
The gun requirements are pretty liberal (IMHO), allowing 'modern' gun mods and use of two hands.
You can always find a group that goes "Outlaw", permitting the use of ANY and ALL guns of the era - Mauser Broomhandles, Lugers, Colt DA's, SxS's, etc. Then you'd have to accommodate FMJ bullets, etc.