A few years ago I went prairie dog hunting with a .223. Loads used IMR8208xbr, and the rifle is not a copper magnet. Left with a clean bore except for the 5 shots after cleaning to foul the bore and confirm sight in. Shot 440 rounds without cleaning and kept my last 20 for a check. At the range at home, no change in group size after the 440 rounds. Rifle cleaned up quickly, some powder fouling but not much and very little copper. I don't clean that rifle as often anymore! Other rifles will need cleaning more often, but nothing needs to be cleaned oftener than every 80-100 rounds. I have owned copper foulers that needed more fequent cleaning with a good copper solvent, but those have gone down the road. I live in a dry climate so rust is not an issue.....Lousisana shooters may need to worry more.
Indeed we do as a .222 barrel I once owned can attest. No feeling like looking down a bore and seeing fuzzy crud in it and when pushing a patch through it comes out red.
