If all you own is an AR in 223, spend some money and look for one of the drop in 22lr set ups, I have one of the old colt models, and its only used in a 67 AR with the slow twist, but they may work in the newer models, I still use the standard "Game Getters" from CCi and it does fine on rabbits, for squirrels I still use the Marlin 39 and shorts