.22 Caliber

 

The .22 Long Rifle rimfire cartridge is a long established variety of ammunition, and in terms of units sold is still by far the most common in the world today. The cartridge is often referred to simply as .22 LR. It is occasionally referred to by its metric designation of 5.6x15mmR

By combining the casing of the .22 Long with the 40 grain bullet of the .22 Extra Long. For many decades, it has been a very popular cartridge around the world. It is one of the few cartridges that are accepted by a large variety of rifles, as well as pistols. Virtually every manufacturer of cartridge firearms makes at least one model chambering it.

The .22 Long Rifle and related cartridges (.22 Short, .22 Long and .22 Extra Long) use a heeled bullet, which means that the bullet is the same diameter as the case, and has a narrower "heel" portion that fits in the case.

.22 LR is effective within 150 meters (495 ft). After 150 meters the ballistics of the round are such that the large "drop" will be difficult to compensate. The relatively short effective range, low report, and light recoil has made it a favorite for use as a target practice cartridge.

.22 Long Rifle bullets are generally either plain lead associated with standard velocity loads or plated with copper or gilding metal associated with high velocity or hyper velocity loads. The thin copper layer on the bullet functions as a lubricant and reduces the friction between the high velocity bullet and the barrel thus reducing barrel wear. It also has the effect of preventing oxidation of the lead bullet. Lead tends to oxidize if stored over long periods of time; as a result of this, the bullet's diameter could increase to a level that may prevent the insertion of the cartridge in the chamber.

Good quality .22 LR ammunition can be quite accurate. Its main advantages are low cost, low recoil, low noise and high accuracy-to-cost ratio.

 

Specifications

Muzzle velocity (nominal):

  • 40 gr (2.6 g) lead: 1082 ft/s (330 m/s) .22 LR Subsonic
  • 36 gr (2.33 g) copper plated lead: 1328 ft/s (405 m/s) .22 LR High Velocity

 

Note: actual velocities are dependent on many factors, such as barrel length of a given firearm and manufacturer of a given batch of ammunition, and will vary widely in practice. The above velocities are typical.

 

According to the official C.I.P. guidelines, the .22 LR case can handle up to 205 MPa (30,000 psi) copper crusher (measuring method crusher conformal) pressure. In C.I.P. regulated countries, every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers. 


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