A Timeline of the Rimfire Family: From the CB Cap of the 1800s to the .21 Sharp

zab nab 1 w

A timeline of the rimfire family from the CB cap of the 1800s to the .21 Sharp, with the shotshell milestones beside it.
Rimfire design is older than most people think. The ignition system dates from the 1800s, and the family has been growing ever since. This timeline follows it from the CB cap to the .21 Sharp, with the shotshells that grew up beside it.
The 1880s and 1890s
The .22 LR arrived in 1887 and has outlived nearly everything else, and subsonic loads for it are at subsonic 22lr ammo. The .22 CB, a low-power cap cartridge descended from Flobert's designs, dates from about 1888, and its loads are at 22 cb ammo for sale.
The .22 Winchester Rimfire, or .22 WRF, came in 1890 with the Winchester Model 1890 slide-action rifle, and its loads are at 22 wrf ammo.
The 1900s
Winchester introduced the .22 WMR in 1959, on a lengthened WRF-style case, and its loads are at 22 wmr ammo.
The 2000s and 2010s
Hornady's .17 HMR arrived in 2002 as a necked-down .22 WMR, and its 17-grain loads are at 17 hmr 17 grain ammo. The .17 HM2 followed in 2004. The .17 WSM, from Winchester in 2012, has the highest velocity of the family, and its polymer-tip loads are at 17 wsm polymer tip ammo.
The 2020s
Winchester announced the .21 Sharp in 2023, a .22 LR case with a smaller bullet, and its loads are at winchester 21 sharp ammo. It is the newest of these rimfires.
Shotshells along the way
Shotshells have their own timeline. The Brenneke slug dates from 1898, and Foster-type rifled slugs from 1931. Fiocchi, an Italian maker founded in the 1800s, loads slugs today, and its 12-gauge slugs are at fiocchi 12 gauge slugs.
In 1991 the United States prohibited lead shot for waterfowl hunting nationwide, which made steel the standard, and 20-gauge steel shot is at 20 gauge steel shot ammo for sale. In the 2010s the 1¾-inch minishell reached the American market. Some makers market minishell loads for personal defense, a use that calls for testing the shotgun's reliability and following local law, and minishell self-defense loads are at 12 gauge minishell self defense ammo.

Dates are as generally reported and may differ slightly between sources. Match the marking on your gun to the box, and confirm current stock and state shipping restrictions before ordering.