[Doug G.]

Dwight, having shot black powder guns for many years I have heard thousands of cleaning methods. I still use dishwater soap mildly warm on a swab, then go to a brush. I run patches through the bore until dry. The ammonia in the 409 is ok in that it is diluted, but what he is probably seeing is lead residue that the ammonia is dissolving. I think that if ammonia is left on too long it can ruin blue and possibly etch metal. I sometimes follow up with good old Hoppes No.9 after.