The barrels that really benefit from proper breaking-in is the little ones used for shooting ground squirrels, etc. I an referring to .17's (or smaller) and .20's. Here, I'm talking about firing one shot and cleaning, then another and cleaning, etc for 10 shots, then 3 shto groupsa nd cleaning until 5 groups are fired. After that, with good custom barrels, routine cleaning is if and when accuracy drops off- which may run form 50 to 600 rounds depending on the calibre and amount of powder being burned.
; The benefit isn't in accuracy, it's in shooting cleanly, without picking up an copper (guilding metal) fouling.
; Having a .17 that's running 4,000fps yet not copper fouling is a blessing. The 3 groove PacNors are the best of the best in this regard and seldon foul is broken in properly.
; Big game rifles with produciton factory barrels may foul less with carfeful breaking in, but I've never seen it. Any I've had all fouled to some extent, some more heavily than others. They get cleaned every time they're used.
; The .17's I'm referring to, get cleaned every 200 to 400 shots depending on the weather - wet or dry. It's all they need, and Ed's Red is all the solvent taht's needed. It's pretty much a powder solvent only.