As most have said...clean it good with a snug fitting patch then go shooting. If this were a benchrest/target barrel I would do thing a tad different but not much.
JB bore past WON'T hurt your barrel OR remove metal...it is great for removing copper fouling and you might just need some depending on how rough your bore is...so is Montana Extreme copper remover and Wipe-0ut or Patch out.
Flitz will remove metal but it take a conserted effort and anywhere from 500 to 1000 strokes to remove 0.0005" -0.001" of metal or so...valve grinding paste will certainly do a job on it and turn it into a smoothbore for shooting shot cartridges. I've used Flitz many times to polish up a rough barrel 50 strokes at a time with a couple of patches wrapped around a nylon brush. Not sure if it really helped in the accuracy department on a couple as the groups were running a half inch or slightly better, but is SURE helped to keep the copper fouling down and made it easier to clean out. Doing the polish job helped keep an early 17 Rem Remington barrel shooting for an additional season...maybe 2-400 more rounds.
Ben doon dis a very long time with shooters from military POS's to benchresters and I've NEVER hurt a barrel by cleaning it and I've used just about every product that ever came on the market for the past 50 odd years...including JB bore paste.
Use it with a little Kroil, ATF, or ANY KIND of light weight oil.
For a quicky polish up and pot stir up use a cast lead bullets with a little 800-1200 grit rolled on them and read up on the "FIRELAPPING" break in proceedure for some light, hilarious, teeth gnashing propaganda....
hahahahahahaha.
Just clean it, shoot it and enjoy it.
Luck
