Gentlemen,
I ordered some slix nipples, found they don't fit my early 1970's colts. I did find though, fitting new standard nipples from TOW worked a treat. I did cowboy action for about 12months and only used my Navy and 3rd Mod Dragoon. Found the Navy would jam regularly, so put in a new set of nipples and look no jams !! I found after regular use after about 15 months I started getting jams again, so another new set of nipples from TOW were fitted and lo, no more jams !! I guess the biggest problem is the nipples gas cut over time, then spread cap fragments every where. New nipples seem just to allow the cap to split into 3 and the wings stay together. Occasionally I get a cap stick to the hammer face, but as I am only target shooting now, there is time to check after each shot, and it happens only rarely.