Lee REAL in a 1858?

[Hellgate]

I just smeared my BP lube into the grooves ahead of time and put them into an empty bullet box.

 

[pascalp]

Try to find a Lyman 450229, they were made for what you want.
Wheight was quite conservative, slighty heavier than round ball (near 145gn), wide driving band for acuracy, hollow base to accomodate chamber and bore dimensioning and SWC to cut a cylinder thru the target.