Have a few different cast loads, some GC some PB from Beartooth, barrel looks pretty clean, if there is leading it is hard to see and makes me think there can't be a whole lot. What I am noticing, is with a clean barrel, most of the cast loads will print to the center of the target, after maybe 10 rounds, point of impact will shift a little toward the left where it will settle and stay through the rest of the range session. If I clean it again, or run some j words through it, point of impact returns back to center and will walk back toward the left by a couple of inches within 10 rounds again.
Gun is an Old Model Vaquero, 4 5/8" barrel, cylinder throats are reamed to .4525" and the barrel is Taylor throated, so there are no constrictions, it doesn't spit, it's really a good shooter. Boolits are sized .452" and velocities are typical for Ruger Only, 22 - 23gr H110 under a 340gr GC or a 325gr GC.
What jag or cleaning material would you recommend to maintain this bore and keep it shooting to center? Brush wrapped with Chore Boy between strings of fire?
Also, these are lubed with that hard blue lube that Beartooth uses, could that have anything to do with groups shifting point of impact or would using softer lube like Felix make a difference?
Note: If I take this gun home and run just a bronze .50 brush through it, not much comes out of the bore but a little black powdery burnt powder residue, if it is leading, it's very minimal unless I just can't see it.