Load those up and I bet those will make things leak
Hank
Yep, they do well. However, I get better accuracy out of my rifle with the flat base Barnes muzzleloader bullets which are essentially the same, with no grooves and no boattail. I think the boattail was a mistake for this cartridge, but that is what many wanted.
Copper fouling is very minimal with either. 2430 fps with the T-EZ bullets and 2540 with the TTSX from a 16" Ruger. Same load.