Getting back to Butches Bore Shine I just cleaned a 17 HMR and a 220 Swift using the BBS. If u use a copper jacketed bullet this stuff works! The 17 HMR had 223 rounds thru it and it cleaned up like new. They recommend to clean thr 17 HMR bore only when the groups open up. I have shot 6 Yoted so far with this tack driver. The Swift I clean after every shooting session. As far as BP I really don't know what it's effects are. I used a bunch of JB Bore Compound ona 50 cal Rem 700, Knight BK 92 and a new Omega. ThenI used BBS and the bore shines like a mirror.