Wouldn't this depend on what, environment, purpose.... I mean for defensive purposes - short range / long range, hunting big game / small game. there are a lot of variables but I think I will shoot what ever I have the ammo for and what ever I can get.:What do you think the best caliber weapon to have would be in a SHTF situation?
i say 5.56x45 NATO due to its use by LEO and Military.