I thought I would relay some info I picked up a while back.
A friend of mine was trying out a new inline ML of a famous maker.He was getting horrible accuracy with his sabot/bullet combo,something like 48" at 100 yds.He was able to return it,in exchange for another inline by the same maker.Same results,horrible accuracy.We were baffled.
He went back to his old muzzleloader with a different load for the hunting season.
Some months later, in my internet journeys,I ran across an article about using lead conicals in sabots.In it the author mentioned how using hollow base conicals in sabots would not work as the hollow base would expand on firing,cutting the sabot ,and resulting in horrible accuracy.I called my friend up,and sure enough,the bullets he had been using were hollow base conicals.Once he started using the correct size and configuration of bullets,accuracy was restored.