Originally Posted By: ginge
I believe the 12 guage is 3 inch: wonder what buck shot or turkey shot I could safely shoot?

ginge I cringe if that gun has 3" chambers DO NOT put modern 3" magnum loads in it.
I would even go as far myself, to not put any modern factory loaded high speed & pressure 12g 2 3/4 loads through it.
Do we know the chokes on the 12g barrels ?
O.M