Appears it could be lead which used to lap the barrels during the manufacturing process. I would clean as normal and proceed to shoot.This is a vanguard II in a 257 WBY. It's been in the safe for 3 years, never been fired. Was gonna use the action for something else. Recently I've decided ( after reading a thread on hear about shooting 90 gr hammers at 4000+) I decided to bed, float, buy brass, bullets, Varget, and H4350. Should have looked down the barrel first. This is towards the end and about the half way mark. It almost looks like it can be punched off the surface, but what do I know. I've scrubbed it pretty good for a while now. Was wondering if the experts here have any advice. ThanksView attachment 365139View attachment 365140
Did it still shoot well for the shots before it got loaded up? Having to clean a bore every couple of rounds would be a deal breaker for me even if those couple of rounds shot perfect.Here is some pictures I took of my barrel before I got rid of it.You can see how the copper loaded up just after a couple of rounds.
Never shot better than 2".This was farther down the barrel after three rounds.Did it still shoot well for the shots before it got loaded up? Having to clean a bore every couple of rounds would be a deal breaker for me even if those couple of rounds shot perfect.
Try lapping it ?Never shot better than 2".This was farther down the barrel after three rounds.View attachment 365236View attachment 365237View attachment 365238
Bore scopes should be illegal. They make too many people believe there is a problem, when no problem exists. Just shoot it. It's likely to shoot half minute or better.
If you borescope a barrel, and there isn't a raccon nested in it, just shoot it. Those pictures mean nothing.