The RB in a .58 is a different animal than a .50 RB. Quite a bit more oomph. I have a Zouave replica that will shoot PRB into 6" at 100 yds, about the same as it does with the Lyman old style Minie. There's something about carrying that gun, it makes me feel invincable! 10 ga, I might be able to whip up 50 of the old style Lyman Minies, .58. It'd take a month or two, got a long list of to-dos. Let me know if you're interested and what you have for trade. I have built up a good supply of pure lead, it's just these suckers are slow to produce.