My experience is similar to 10pt's, you need to keep them clean, particularly if using BP, Pyrodex or T7 in a muzzleloader. After 2 day's in the rain my buddys stainless ML was oozing rust out of the frame. I use a good paste wax on everything I can coat and that works pretty well. I also am using BH209 powder now and it's less of a problem, you just need to keep it wiped down.