I think you also need to define what the purpose of the replacement is for.
-Rifle using .223 or 7.62 rooskie rounds? A nice bolt action works.
-Varmint gun? lever action, M1 if you REALLY don't like varmints.
-HD? Shotgun.
-Tacticool mall operator equipment? Lee Enfield bolt action. Nothing says tacticool operator like a ninja operating a .303 in mad minute mode.