Honestly,
I've had nothing but good luck and shot pretty much nothing but .575 minies thrown from a Lyman mold. I've cast and shot a couple thousand of them too. Rifles used are a Pedersoli 1861 Springfield (my main shooter), Armi Sport 1855 Springfield, Armi Sport 1862 Richmond rifle and an Armi Sport 2-band Enfield.
Performance is pretty uniform from all of them. I always cast with pure soft lead and never load over 60 grains as pressure gets too high and apparently you will blow the skirt. My settled on load, and what I preload all my cartridges with, is 55 grains of Goex 2f. I use SPG lube as well. I also have vinyl speed load tubes from Dixie that I load with powder, insert the Minie ball tip down into the tube leaving the grease rings exposed. I melt a stick of SPG in the microwave and simply dip the minies to lube them. Works great and the air pocket in the hollow base actually keeps the lube almost completely outside in the rings.
Almost all of the store bought minies I tried ages ago before casting my own really sucked. I don't shoot round ball through any of these rifles either as they were made for minie balls. I'm a Civil War reenactor so keeping to tradition and only shooting minies is kinda the point for me.