In 20ga - 7/8 to 1 1/8 oz bismuth 4's. 1oz to 1 1/4oz lead 4's or 5's. I've killed a lot of birds this year with 7/8oz Boss 3/5 loads, and 1 1/4oz lead 4's have been long range hammers.
28 gauge, 3/4 ounce #6 steel is getting it done for me. O/U 28 gauge with IC bottom, mod upper bbl. Haven’t lost a bird thus far. Helps to have good dogs. MTG
Non-tox Boss Bismuth 3" copper plated#5 1-1/8oz. I haven't used either new copper shot but have heard good reports. Kinda spendy but way better than steel.
My go to 20ga lead load is Fiocci Golden Pheasant 3" nickel plated #5 1 1/44oz. 203GP5