I were going to cast conicals for my TC, I'd probably cast an all lead, well lubed oversized projectile.
There is a heck of a difference between loading a tight sabot and loading an over-sized ball, or Minie style projectile. I tried a Hornady FPB which is a copper jacketed "no skirt" Minie style projectile. They looked cool and worth trying. They mic out at .507 at the base. It was "hernia class" hard to load in the T/C. Might be much better in a different gun.
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