There was the 22 Gustovsen (sp?), which was a necked down 30 carbine, IIRC, but it lacked case capacity. Then cam the .224 Winchester. It had the same case as the current 223, but a shorter, stubby 52 grain bullet. It was designed for the Winchester Light Military Rifle. Armalite used the .222 Remington special (longer than the 222 Remington) that was renamed .223 to prevent confusing the two rounds.