BlackMag3 was advertised by the manufacturer as non corrosive. I noticed that Cabelas did not call it non corrosive. I bought a pound of it to find out for myself. I fired one shot from my cap and ball replica pistol. Thank God, I ran a patch down the bore, before I let it set up for a month. I had rust all over that one cylinder and the hammer. Took me about 3 hours to clean it up, the action is still a little rough.