Gun Digest presents ... Cartridges of the AR-15! Noted gunwriter and AR-15 expert Patrick Sweeney lays out the ever-increasing field of AR-15 cartridges. Whether you're interested in AR-15s for home defense, long-range shooting, or hunting, there is surely a cartridge that meets your needs. Sweeney covers them all, from the 5.56 NATO/.223 Rem., to rimfires like .22LR, up to the .300 AAC Blackout, 7.62x40 Wilson, 6.5 Grendel, .264 LBC, .30 Remington AR, .300 Win. Mag., .338 Federal, .450 Bushmaster and many, many more!