Ok, some scopes say they're rated for .22 at best, but not many others say their limits. I'd like to know how to tell if a scope is suitable (or which models are suitable) for: 1.) .223 2.) 7.62x39mm 3.) .308 4.) .30-06 5.) .300 Win Mag 6.) .300 Rem Ultra Mag 7.) .338 Win Mag 8.) 12ga shotgun I mounted a $30 Tasco scope on my HK-91 clone, and after getting 4" groups, I wonder if I've been using an insufficient scope. If so, would that scope still be usable on lesser powered guns, or is it ruined. And this was a while back, when I wasn't as bright, but I stuck a low end Simmons scope on my Mossberg 500. Think I ruined it too, or may I in fact have been spared from my stupidity?