Thank you both, I've loaded bismuth for both 16 and 12 using same volume as lead - the 10 is a new toy and was looking for a bit of guidance which I now have 👍
Anyone know where I can get some 10bore bismuth reloading info? I know steel is cheaper but not good for a damascus barrelled 2 7/8 chambered hammer gun and I've managed to acquire a few lbs of bismuth at a sensible price