Non toxic shot for old guns

I'm about to go goose hunting and would love to use my Winchester M12 heavy duck or my old 97. Problem is they're both full choke barrels. I know steel is a no-no in old guns and full chokes not designed for steel, so I'm up to a double no-no...

Is there any other non toxic shot out there that would run in these old full choke guns?

Damn.... After looking around at the store during lunch I started to wonder if it would be cheaper to have the choke opened up a little bit and get it chrome lined!

Just kidding though, don't want to modify them... They're still damn near original, except for the butt pad on the 97. Guess I'll just go with steel shot and the newer shotties until I hit the lotto.

My understanding is that it's not just the choke, but the entire barrel will get torn up from firing steel in these old guns. Am I mistaken?

Only 1 of my M12's would probably be considered collectible which is the "heavy duck" model. I have a 16 gauge field grade 28" modified which was manufactured in 1941. It was my 1st shotgun, but due to being caught in a flood and the original stock being cut down I had to have it reblued and restocked. Maybe it's a candidate for some modernization. The other is a 1925 manufactured 12 gauge. It has one of those god awful poly chokes on it and is missing the butt plate - not sure what to do with that one yet.

My 97 is a full frame (not takedown) 30" full choke with ordinance marks on the receiver. Not sure what it's worth, but I don't want to mess with it due to the flaming bomb stamped into the receiver. I'm sure it's no where as valuable as a trench gun or anything, but it's got to be worth something.

Thanks for the advice.. The local cabela's didn't have any tungsten in stock though... Will have to dig around online.