Sizing a Minie Bullet

[Cannonman1]

I have an original .54 Mississippi with a bore measured at .526 .. I want to use a Minie bullet and have a Lyman mold in .533.  Is is practical to size a minie bullet down to .525 ??  or is that too much of a reduction

[LongWalker]

Maybe.  A lot will depend on the thickness of the Minie's skirts, the size/shape of the hollow in the base, and the leade angle in the sizing die.  If you go with something like a LEE or NOE push-through sizing die, you can try a .525" die but may find that an intermediate die (.529" or so) will make sizing in the .525" die work better. 

Over the years, for special projects I've sized bullets down from .460" to .449", and a few times from .452" to .432".  Each time I found that I had better results if the lube grooves were filled before sizing, and if the lubed but unsized bullet was additionally coated with a wipe of Johnson's Past Wax or similar product. 

Good luck!