I agree on .45ACP being way to go v GAP. I'm fan of, in a pinch, being able to visit a hardware store, online merchant (Midway, Brownells, etc) sporting goods store, Walmart, AnyStore USA, & readily finding ammo that I can shoot. This includes calibers like .30-06, .308, .270, 9mm, .40cal, .45 ACP, etc. While the GAP isn't necessarily a wildcat cartridge, it doesn't fit the "when zombies attack" grab lots more ammo philosophy. While I own a custom AR in 6.8mm Rem SPC, & it shoots like a dream, I might not have made the decision again v. .308 platform, simply based on ammo availability & it appears to be actually growing a bit of a following. My small team opted to carry AK-47s overseas for simple reason that if we ran out of ammunition in a pinch, we knew our adversaries would leave plenty of 7.62X39 ammunition for us to use. In that instance, NATO ammo didn't fit the zombie attack criteria any more than I don't think .45GAP does here.