Ive had remington new rifle barrels come out black as coal on the first cleaning patch right out of the box. If everything looks brand spanking new ,even the outside of barrel, action ,stock I'd say it's a new gun not to sure what you see as fire cracking is fire cracking. If it was shot that much you would see some sort of wear marks on the bolt and action rail. shot that much and never put a ding or scratch on it must of been really careful with it. But always a possibility, but I'm not convinced it was used.