A large hole in the muzzle of your AR-15 might help keep you alive if the world falls apart. Here are three big-bore cartridges compatible with your go-to AR-15 lower that can keep you fed.
One of the more-popular AR-15s on the market today, the Ruger AR-556 can now be had in the big-bore 450 Bushmaster. See our range experience with it here.