I don't know anything specificaly about the Vangaurd,but with such poor accuracy I am also thinking that it may be an issue with your scope,or mounts.Have you tried it from 100 yards with the current scope?.If it's just an old spare take off scope with out adjustable objective it may actualy tighten up a little at 100 yards.Are you shooting store bought ammo?.If it was mine,and I couldn't get it to improve I would just keep it for a truck gun like the guy you got it from.I know people rebarrel them,but unless you can do all the work yourself,and enjoy it as a hobbie I don't think it would be worth the expence,or your time.
