Another good trick, is to get someone else to shoot it without giving them any hint of the issue you're having with it. I'm not sure what your standards are for this rifle or how many rounds per group, how quickly you're shooting, or which ammo.I would clean the hell out of the barrel and make sure I use a proven scope with tight mounts and try again. If it still sucks, it's easy to fit a new barrel on.
^^ This ^^ as well as a scope/mounts check. Bedding? Ammo? Lots of variables.I'd get the copper out of that barrel and shoot it again before deeming it shot out.
No, but it might indicate the reason it does not shoot well. It will show you things not seen with the naked eye esp if the bore has a nice shiney coating of oil.A borescope cannot tell you if a barrel will shoot well.