If your speaking of Lymans #575213 .58 Cal Minie 566 grain mold, I got one with the PH Musketoon I bought a while back.
It fits the Lyman Large handles (and other large size handles, I'm sure).
The Minie bullet it casts (at least in my mold) is .576-.577 in diameter, 1.064 long with 3 grease grooves.
The base wall thickness is .060 and the pocket depth is .220.
I've only shot about 30 of these and the accuracy at 50 yards was pretty good. I was using about 65 grains of FFg.
Actually, I wasn't shooting for a group size, just to have some fun sending large chunks of lead downrange.
They loaded easily in the Musketoon and caused the little gun to recoil rather smartly.
One of these days, I'm going to try them in some of my other .58s. As they are 2 and 3 band guns, I suspect the recoil will be a lot easier to manage.
Maybe someone else can tell you more?
zonie