The .220 Swift is a semi-rimmed rifle cartridge developed by Winchester and introduced in 1935. It was the first factory loaded rifle cartridge with a muzzle velocity of over ft/s ( m/s). Until the introduction of the .223 WSSM the 220 Swift was the fastest commercial cartridge in the world. Due to its very high velocity its bullet drop allows dead on sighting on game such as groundhogs to ranges out to yd ( m), and it is still considered an excellent cartridge for taking varmints by experienced Swift shooters.