The .303/22, sometimes known as the .22/303, is a wildcat centrefire rifle cartridge based on the .303 British, necked down to fire a .224 projectile, originating in Australia in the 1930s as a cartridge for sporterised rifles, particularly on the Lee–Enfield action. Similar versions also appeared in Canada around the same time. Variants 303/22 Wasp 1.97", 303/22 Varment R. 2.031", 303/22 Sprinter 2.100", 303/22 2.185", 303/22 Shannon 2.222", 303/22 Rocket (aka. 22/4000) unknown case length.