Rimfire cartridges

Rimfire cartridges are still manufactured but only in 0.22 and 0.17 calibers and all other modern firearms ammunition is centerfire (central-fire). 

The majority of the propellants analyzed were from kneecapping incidents involving the use of handguns. A total of 194 propellant samples were analyzed of which 92 were single based. Rimfire cartridges and rifles are rarely used in kneecappings. 

Winchester has three lead-free rimfire cartridges round nose, truncated hollow point and magnum. 

In the rimfire ammunition, such as caliber. 22 cartridge there is no primer assembly as described above, but the primer compn is spun into the rim of the cartridge case and the pro-pint is in intimate contact with the compn. 

Centerfire cartridges were produced by Pauly in 1808 but it was not until 1854 that the firm of Smith Wesson perfected and patented both the centerfire and rimfire metallic cartridge case. Since this time cartridge development has consisted of many small improvements, some resulting from advances in... 

Priming compositions for centerfire ammunition are housed in small metal cups which fit into a recess, called the primer pocket, in the center of the base of the cartridge case. In rimfire ammunition the priming composition is housed inside the cartridge case in the hollow perimeter of the base. 

At this time a typical. 22 caliber rimfire primer composition was the United States Cartridge Company s NRA which was ... 

In the rimfire primer, an integral part of the small-calibre cartridge, the ignition mix, or primer composition is slurried into the cartridge base, crimped, then oven dried at relatively low temperatures (<110°F). The base of the cartridge serves as the striking surface, and the top of the crimp, supported by the weapon breech lip, serves as the anvil. 

Federal has made CCI s TNT Green available for small game in 17 HMR rimfire. The cartridge features clean-burning propellants behind a 16-grain TNT hollow point at 2500 fps. 

---