I've used clr pretty religiously on my rifles for 4 seasons, every 200-300 rounds for prs cartridges like bra dasher and gt. All have lasted 2000+ rounds with no I'll affect in accuracy. Mainly targets throat and chamber neck carbon occurring areas. Follow that with some eliminator, a handfull of strokes of thoroclean, then some more eliminator and then alcohol, and barrels are very clean. They take 10-15 fouling rounds to get back stabilized known velocity, but that's my procedure. Larger cases like standard short mags or prc, get this treatment every 100 rounds. If it's a big magnum or burning dirty hot powders like N570/RL33 they get this treatment every 50-70 rounds. The bigger cases take less rounds to settle back to know velocity. My experience and observations.