What is .22 win auto?

.22 Win Auto is a rimless, centerfire cartridge designed for use in semi-automatic firearms. It was introduced by Winchester in 1903 and was one of the first commercially successful semi-automatic rimfire cartridges. The cartridge features a .22 caliber bullet with a muzzle velocity of around 1,300 feet per second. It has been used for a variety of purposes, including hunting small game and plinking, and is still in production today. However, it is less commonly used than other rimfire cartridges such as .22 LR.