I'm not advocating doing it, but I have shot #2 steel through my '62 Model 12 Mod. choke. Also #6 Hevishot with no ill effects. No ringing of the barrel in front of the choke or change in diameter. (I checked before and after with dial calipers) I wouldn't do it if it were a Full choke. I've seen those ringed. And there is always the differences in steel from generation to generation to consider also.. Steel shot is no bueno por nada.
So no modern shot at all? Looks like I have an excuse to buy another shotty.
How early of models are we talking about? I googled the subject and came up blank.Ask them about short chambers in the early guns and the forcing cone set up for paper hulls vs modern plastics.