Some of the smokeless shooters are using pre-engraved jacketed bullets without sabots. I almost brought up the danger potential as well but have been curious about this for a long time. I'm thinking a guy could get away with a bore RIDING Rainier with a gas seal at the rear. But there is risk (I really cannot testify to the risk myself as I don't know anyone that's tried such a method) and the first few shots should probably be "string fired" from behind a tree.

Given the low cost and great performance of good lead conicals there is not much reason to take the chance.