Just used Frankfort brass cleaner, lot of work, no corrosive deposits, no pitting. 10x magnifier to inspect.Oxide? Hard abrasive?
Don't have access to one.Sonic cleaner?
.40
Thanks.If they where mine I would load them.
Lubalox ®Exterior CoatingNosler and others make out pretty good with 'black' rifle bullets.
Lubalox ®Exterior Coating
Reduces fouling, pressure and friction between bullet and bore; provides longer barrel life, easier cleaning and enhanced accuracy.
I think, not the same as the OP bullets.