Bonanza,

None. When my dog died last year I put up my guns, because I lost interest in hunting. This year I took the Zihn 16-bore out, still loaded from last year, and aimed at a 1-gallon plastic bottle filled with water at 95 yards. The rifle fired with a sharp crack, and the bottle exploded and was laid out like a bath towel. I rolled it back into shape, and the entry and exit holes were both centered. After two wet patches, two dry patches, and one patch with T/C Bore Butter, the bore was completely clean.

I also have a T/C 54 cal percussion Renegade, a Custom Shop gun with 30" barrel and 1:66" twist. It has only been loaded with 777, and has fired hundreds of shots. The gun hasn't been fired for about three years. Just now I ran a tight, dry patch down the bore, and it came out completely rust free, and with a slight yellow stain from the T/C Bore Butter. The patch smells of wintergreen.

Magnified examination of the bore of both guns reveals no blemishes whatsoever. The stuff offends some traditionalists, but works wonderfully. It cleans up so easily and completely, that bores can be maintained in like-new condition with minimal effort.