iam thinking of having a barrel refinnished, when i take it to get black oxided should i plug the bore or not ? i am not sure if shooting while their is oxide in the bore if that will screw my bore up or not ( hk polly rifling )
Don't worry about it. After a few shots everything burnishes back to where it was. Blueing/black oxide is done at 290-305 degrees. There's not much you could plug it with that would hold up well anyways.
Won't hurt anything. We don't plug barrels with a caustic blue/black oxide process (like said above, your boiling in bluing salts and water at 280 - 300 degrees). Clean bore and chamber after to remove bluing salts and your good to go.
As JR said. Had a "gunsmith" ruin a barrel for me like that, years ago. Then he said he'd lap it out. I could almost hit the head of a 50 gallon drum at 100.