.22 long
The .22 long is a variety of .22 caliber (5.6 mm) rimfire ammunition. The .22 long is the second-oldest of the surviving rimfire cartridges, dating back to 1871, when it was loaded with a 29 gr (1.9 g) bullet and 5 gr (0.32 g) of black powder, 25% more than the .22 short on which it was based.