Well lesson learned with my 457. Accuracy started getting worse over the last 500 rounds or so. It might be good for a couple of 10 shot strings, but then groups would open back up. Thought maybe it was my ammo...had been running mostly Tac 22 and SK HV Match, but broke into a new lot of the Tac so thought that might be it. Tried some fancy stuff...Center X, Tenex and SK Match. Results were pretty ho hum
I had been following the barrel seasoning methodology and only using C4 to clean the barrel since day 1. I use a silicone plug, stuff it in the chamber, close the bolt, put an aluminum rod in the bore and fill it with C4 for a couple of days, then patch it out. Run a couple of dry patches, then a few wet, a few dry, etc until clean.
CZ bores are tight, and my 22 cal rod was no exception. So I would use my CF .17 cal rod to clean...that's basically what started my trouble unbeknownst to me. Because I was using that rod, I had to use a .20 cal jag b/c I didn't have an adapter to use the .22 cal jag. Didn't figure it was a big deal since the bore was tight and didn't want to force it. So after this last range trip I finally got the adapter and tried the .22 cal jag. Did the whole soak thing, but with the 22 cal jag, patches just never stopped being dirty. After awhile it felt like I wasn't gaining so I did another soak for a couple of days, patched it out with the 22 cal jag again and same thing...endless dirty patches. 3rd soak...same thing. WTF. Stuck the bore scope down there and it was patchy as hell with carbon. Could see metal in some spots, fouling everywhere else. So I tried various solvents, including CLR against my better judgement, tons of dirty patches, but no major gains on the scope. Finally got some JB Bore Brite and took it back down to bare metal.
Apparently the 20 cal jag wasn't tight enough to actually remove the carbon fouling from previous cleanings and it just kept building. I always scoped it after cleaning, but for no particular reason I always scoped it after I ran my last patch with oil down it for storage. So all that fouling looked shiny and I just assumed it was seasoning.
Hoping to get it out to the range next week and see if it shoots better or if I fucked it up good with the JB. Worst case, I ordered one of those L3i drop in barrels, not because of this, but because why not for $330. I'll probably just abandon the seasoning method and just take it back down to metal with a rimfire blend from here on out.
I can make them quickly, we just need the demand first.
