Read an article several years ago, before affordable bore scopes, about the condition of some rifle bores. The writer of the article had a borescope and said it would be shocking if you could grab the bullet out of the air after exiting the muzzle after going down the bore. Some bullets would be very damaged due to rust and pits in the bore from lack of proper cleaning. He had a customers 22-250 that some of the bullets would not make it to the 100 yard target due to flying apart due to gouged jacket. The bullets that did make it were keyholing hitting target sideways.