.22 Long Rifle

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 a .22 LR and various rifles, pistols, revolvers, and even some smoothbore shotguns have been manufactured in this caliber. For many decades, it has been the most popular cartridge in the world. Virtually every manufacturer of cartridge firearms makes at least one model chambering it, and this has been true for more than a century. The .22 Long Rifle and related cartridges use a heeled bullet, which means that the bullet is the same diameter of the case, and has a narrower "heel" portion that fits in the case.

The low cost, minimal recoil, and low noise make the .22 LR an ideal cartridge for recreational shooting, and it is often purchased in bulk. The standard box of .22 LR contains 50 rounds, and .22 LR is often sold by the brick, containing 10 boxes for 500 rounds, or the case containing 10 bricks for 5000 rounds.

.22 LR ammunition is available in a very wide variety, and a very wide price range. Bullet weights range from 30 to 60 grains (1.9 to 3.9 g), velocities from 350 to 1750 feet per second (110 to 530 m/s). "Promotional" loads for plinking can be found for under US$10.00 per brick, while precision target rounds can cost US$80.00 per brick. Currently, a standard box of 50 rounds goes for $1.00 US.

Performance

The .22 LR is inexpensive, often costing less than two US cents per cartridge. It is effective within 150 meters (490 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. The accuracy of the cartridge is good, but not exceptional; various cartridges are capable of the same or better accuracy. Still, the effectiveness of this cartridge is often underestimated. The trajectory of the .22 LR "has a 2.7 inch rise at 50 yards and 10.8 inch drop at 150 yards when zeroed at 100 yards." "Practically speaking, a .22 LR rifle needs to be zeroed at about 75 yards to avoid over-shooting small animals like squirrels at intermediate distances." [http://www.chuckhawks.com/17_M2.htm

The newest commercial rimfire, the .17 Mach 2, is based on the .22 LR case, but is slightly stretched in length and necked down. The light, aerodynamic .17 caliber (4.5 mm) bullet gives a much higher velocity than the .22 LR at the expense of a price of several times that of the .22 LR, and of an increased noise of firing caused by the higher muzzle pressure and supersonic bullet velocity. However, the Mach 2 does not exceed the power levels of the "hyper velocity" .22 LR loads, and in some cases the .22 LR exceeds the power of the modern cartridge.

As a hunting cartridge, the .22 LR is mainly used to kill small vermin such as rats and squirrels. It is also highly effective on rabbits at distances closer than 125 meters and on ground hogs, marmots, and foxes closer than 75 meters. It has been successfully used on large creatures such as coyotes, but range should be limited to no farther then 50 meters, and head and chest shots are mandatory with the most powerful and accurate .22 cartridge the hunter can use. The hunter would best find what cartridge out of the various high velocity and hyper velocity shoots well for him by preliminary testing. For greater range or larger game, a more powerful cartridge should be used to ensure a clean kill. Examples include larger rimfire rounds such as the .22 WMR, .17 HMR, or any centrefire cartridge. Like any bullet, the .22 LR is nonetheless dangerous and capable of killing humans and large animals.

Variants

There are a variety of different types of .22 Long Rifle (or ".22 LR") loads. They are often divided into 3 distinct categories:

subsonic velocity (also includes "target" or "match" loads)
high velocity (also known as standard velocity)
hyper-velocity (also known as ultra-velocity)

Subsonic rounds have a muzzle velocity of 330 m/s (1082 ft/s) or less and are sometimes equipped with an extra heavy, 2.9-3.9 gram bullet. Conversely, some rounds contain little more than primer and an extra-light bullet. As the speed of sound in air at 20 °C (68 °F) is approximately 343.4 m/s (1126 ft/s), the subsonic round's muzzle velocity is close to the speed of sound under many hunting conditions, or only very slightly below it. However, under cold air conditions at 0 °C (32 °F), the speed of sound drops to 331.5 m/s (1087.6 ft/s), essentially the same speed as the muzzle velocity of the subsonic round. Hence, a so-called subsonic round when used under slightly colder conditions than 0 °C (32 °F) is often no longer subsonic and instability may arise when crossing down through the speed of sound. To counteract this, some cartridge manufacturers have lowered the speed of their subsonic ammunition to 315 m/s (1030 ft/s) or significantly less, but some manufacturers still sell subsonic ammunition with a velocity only slightly under 330 m/s.

High velocity (standard) rounds have a slightly supersonic muzzle velocity of around 1125 ft/s(350 m/s) and a "normal" bullet weight of 2.5 to 2.6 grams (40 grains). Such .22 LR High Velocity cartridges use a larger, slower burning powder charge to generate near or slightly-supersonic velocities. Note that these rounds generally do not develop these velocities in handguns because the short barrel does not take full advantage of the slower powder. The downside to supersonic rounds is that the bullet often drops to subsonic speeds on its way to the target which can degrade accuracy. The extra power and penetration, however, more than make up for the slight loss in accuracy for applications such as small game hunting.

Many .22 LR cartridges use bullets lighter than the standard 40 grains (2.6 g), fired at even higher velocities. The CCI Stinger was the first "hyper velocity" .22 LR cartridge, and provides a significant increase in velocity over standard .22 LR rounds. The Stinger uses a longer case, a stronger charge and copper plating on a lighter bullet. The case is longer than that of the normal Long Rifle cartridge, yet Stingers will fit in most Long Rifle chambered firearms. The powder is designed to burn more slowly and thus make the most use of the length of a rifle barrel. In the Stinger the extra case length is compensated by a shorter bullet, which is only available as a plated hollow point. 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 an oxidation-preventing effect on the lead bullet. Lead tends to oxidise if stored over long periods of time and as a result of this, the bullet's diameter increases to a level that might both prevent the insertion of the cartridge in the chamber and might cause the pressure in the barrel to rise to a dangerously high level. The increase in pressure may lead to the case rupturing and potential danger to the shooter. Standard and subsonic cartridges tend to use a type of wax for the same purpose.

Hyper-velocity bullets can have a muzzle velocity of 450 to 550 m/s and this velocity is partially due to the light bullets they use. The bullets are usually around 1.9-2.2 grams in weight. However there is a round that is classified as "hypervelocity" that utilizes a 40 grain (2.6g) projectile. This bullet, called the Velocitor by CCI, owned by Alliant Corporation, has a muzzle velocity of 1,435 ft/s (450 m/s). The bullets themselves are in brass cartridges and usually are configured either in solid or hollow-point bullets.

Special shot cartridges, usually loaded with #12 shot (see shotgun shell) in a .22 LR caliber have also been made and these are ideal for pest control at very short ranges. Such rounds will either have a longer brass case that is crimped closed, or a translucent plastic "bullet" that contains the shot and shatters upon firing. In specially-made .22 bore shotguns, the shotshells can be used for short range skeet shooting and trap shooting at special, scaled-down, clay targets.

Usage

Today .22 Long Rifle ammunition is mainly being used for hunting small pests, for sports shooting and for cheap training. .22 LR is the choice for several ISSF shooting events: 50 m Rifle, 50 m Pistol, 25 m Pistol, 25 m Rapid Fire Pistol and 25 m Standard Pistol, Bullseye (shooting competition), plus divisions of metallic silhouette and pin shooting, most high school, collegiate, Boy Scouts of America, Air Training Corps, and 4H shooting events, and many others. With high quality ammunition, the .22 Long Rifle can be quite accurate. Its main advantages are low cost, low recoil and low noise. Its main disadvantage is its low power; it is only suitable for game under 25 kilograms (55 lbs), and as a defensive cartridge it is considered inadequate, though the small size allows very lightweight, easily concealable handguns which can be carried in circumstances where anything larger would be impractical. Despite their limitations, 22 LR pistols and rifles can be lethal and are often used for self defense simply because they are prevalent, inexpensive and widely available to civilians.

Semi-automatic rifles firing .22 Long Rifle cartridges often will work properly only when firing high velocity .22 LR ammunition; subsonic rounds will often not cycle their actions properly. Bolt-action rifles, however, can utilize any of the variants (high velocity to subsonic.)

The tiny case of the 22 Long Rifle and the subsonic velocities (when using subsonic ammunition) make it well suited for use with a firearm silencer. The low volume of powder gasses mean that 22 LR silencers are often no larger than a bull barrel; the Ruger 10/22 and Ruger MK II are common choices, due to their reliability and low cost, and the resulting product is often nearly indistinguishable from a bull barrel model (although weighing far less). Where firearm silencers are only minimally restricted, a 22 Long Rifle firearm with a silencer is often favored for plinking, as it does not require hearing protection or disturb the neighbors. Local government agencies sometimes use suppressed 22 LR weapons for animal control, since dangerous animals or pests can be dispatched in populated areas without causing undue alarm.

Intelligence agencies and military special forces have used suppressed 22 LR pistols for assassinations and for eliminating guard dogs or sentries. Some examples include the use of suppressed High Standard HD pistols by the American OSS, which was the predecessor organization of the CIA. Gary Powers was issued a suppressed High Standard for the flight in which he was shot down. Suppressed Ruger MK II pistols are in current use by the US Navy SEALs.

The .22 LR has also seen limited usage by police and military snipers. Its main advantage in this role is its low noise, but it is usually limited to urban operations because of its short range. One weapon designed for this purpose is the Russian SV-99 rifle.

Specifications

Standard dimensions are as follows:

Case length: 15 mm (0.595 in )
Case diameter: 5.71 mm (.225 in)
Bullet diameter: 5.68 mm (.224 in)
Rim diameter: 6.88 mm (.271 in)
Rim thickness: 1 mm (.040 in)
Cartridge overall length: 25 mm .985 in
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 lot of ammunition, and will vary widely in practice. The above velocities are typical.

Compatible ammunition

The .22 Long rifle uses a straight walled case. Depending upon the type and the feed mechanism employed, a firearm which is chambered for .22 Long Rifle may also be able to safely chamber and fire the following shorter rimfire cartridges:

.22 BB, in cap, short or long lengths
.22 CB, in cap, short or long lengths
.22 Short
.22 Long

The .22 Winchester Magnum Rimfire, also called .22 Magnum or .22 WMR, uses a different case, which has a significant taper and does not use a heeled bullet. Firing a .22 Long Rifle or derivative in a .22 WMR firearm will likely result in a potentially dangerous case rupture.

External links

Pistol and rifle cartridges

.22 lfB | .22 LR