.22 Winchester Magnum Rimfire

The .22 Winchester Magnum Rimfire (5.6×27mmR), more commonly called .22 WMR, .22 Magnum, or simply .22 Mag, is a rimfire cartridge. Originally loaded with a bullet weight of 40 grains (2.6 g) delivering velocities in the 2,000 feet per second (610 m/s) range from a rifle barrel, .22 WMR has also been loaded with bullet weights of 50 grains (3.2 g) at 1,750 feet per second (530 m/s) and 30 grains (1.9 g) at 2,250 feet per second (690 m/s). More recently, a high-quality 30gr Vmax cartridge from Hornady has been released. This exceeds 2200fps in a rifle and has a reputation for much greater consistency and accuracy than was previously attributed to this calibre. Accuracy around 1 MOA is achievable and this has led to this cartridge regaining ground previously lost to the excellent .17 HMR, especially as the 30gr bullet weight (nearly double that of the HMR's normal 17gr) gives it a reputation for hitting harder on larger varmints such as fox and coyote.

History

The .22 WMR was introduced in 1959 by Winchester, but was not used by Winchester until the Winchester Model 61 slide rifle could be chambered for it, in 1960. By that time, Smith & Wesson and Ruger had revolvers for it, and Savage had come out with the Model 24 and since late 2012, the model 42, a more modern update than the 24, a .22/.410 rifle. It was the only successful rimfire cartridge introduced in the 20th Century.