The .22 Winchester Magnum, most commonly called .22 WMR (for Winchester Magnum Rimfire) or just .22 Magnum, is a rimfire rifle cartridge. Commonly loaded with a 40 grain (2.6 g) bullet, it can deliver velocities in the 1900 ft/s (580 m/s) range from a rifle barrel. A rimfire is a type of firearm cartridge. ... Rimmed, centerfire . ...

History

The .22 WMR was introduced in the 1950s by Winchester, and it was the only successful rimfire cartridge introduced in the 20th century. The .22 WMR uses a larger case than the more popular .22 Long Rifle, both in diameter and length. The .22 WMR's case is also much thicker, allowing much higher pressures. The combination of more powder and higher pressures gives velocities over 2000 feet per second (610 m/s) from a rifle, and 1500 feet per second (460 m/s) from a handgun. The Winchester Repeating Arms Company was a prominent American maker of repeating weapons during the late 19th Century and the early 20th Century. ... .22 Long Rifle - Subsonic Hollowpoint (left), Standard Velocity (Centre), Hyper-Velocity Stinger Hollowpoint (Right). ... A rifle is a firearm with a stock and a barrel that has a spiral groove or grooves (rifling) cut into its interior. ... A handgun is a firearm small enough to be carried and used in one hand. ...

Uses

Since the .22 WMR generally uses the same weight bullets as the .22 Long Rifle, it is generally used in similar situations. The 40 grain .22 WMR at 100 yards still retains the velocity of a .22 LR at the muzzle, which can provide improved penetration at all ranges, and more reliable expansion at long range with expanding bullets.

If sighted in for maximum point blank range on a 3 inch high target, the 40 grain .22 WMR can reach ranges of nearly 125 yards. This makes the .22 WMR an effective medium range varmint rifle cartridge. The relatively quiet sound of firing and negligable recoil also make it a very pleasant rifle to shoot for extended periods of time. It is also significnatly less expensive to shoot than its nearest competition, the centerfire .22 Hornet and the new 5.7 x 28 mm. Point-blank range is the distance between a gun and a target such that it requires minimal effort in aiming it, in particular no allowance needs to be made for the effects of gravity, target movement or wind in aiming the projectile. ... Varmint rifle is an American English term for a relatively small-caliber firearm (or even a high-powered air gun) primarily used for hunting varmints—such as coyotes and smaller. ... A centerfire cartridge is a cartridge in which the primer is located in the center of the cartridge case head. ... The . ... The 5. ...

Firearms using .22 WMR

The .22 WMR operates at pressures beyond what normal blowback actions typically handle, but in the 1990s semiautomatic .22 WMR rifles were introduced by Sturm, Ruger and Marlin Firearms. Before this time, most .22 WMR firearms were bolt action rifles, though the .22 WMR is also found in a number of revolvers by Taurus and Sturm, Ruger, and was previously available in semiautomatic pistols by the now defunct manufacturers AMT and Grendel. Both of these designs used specially designed chambers with flutes or gas ports, designed to lubricate the long, thin cartridge with gasses from the chamber, overcoming the Blish effect and allowing easy extraction of the cartridge. Blowback is a system in which automatic or semi-automatic firearms operate through the energy created by combustion in the chamber and bore acting directly on the bolt face through the cartridge. ... A semi-automatic firearm automatically loads a round into the chamber after the weapon is fired, but still requires a trigger pull for each round that is fired. ... Sturm, Ruger & Company NYSE: RGR is a Connecticut-based manufacturing company composed of three divisions: Ruger Firearms, Ruger Investment Castings, and Ruger Golf. ... A Marlin Firearms Company manufactures Marlin Rifles. ... A bolt-action firearm is one that is manually operated (i. ... The Colt Single Action Army, one of the most popular revolvers of all time For other uses, see Revolver (disambiguation). ... TAURUS is credit transfer agrrement system for SUNY Colleges ... A semi-automatic firearm automatically loads a round into the chamber after the weapon is fired, but still requires a trigger pull for each round that is fired. ... A Browning 9 millimeter Hi-Power Ordnance pistol of the French Navy, 19th century, using a Percussion cap mechanism Derringers were small and easily hidden. ... The Blish Lock is a friction-lock designed by John Bell Blish, that takes advantage of the fact that under extreme pressures, certain dissimilar materials will resist movement through friction greater than normal friction laws would predict. ...

Ammunition

While the .22 WMR is a far more powerful cartridge than the .22 Long Rifle, ammunition is not available in the incredible variety of .22 LR ammunition. Availability is also not as great as the .22 LR; while the .22 WMR is by no means hard to find, nearly every retailer that sells ammunition will carry .22 LR. The price of .22 WMR is substantially higher than almost all .22 LR ammunition, though it is significantly less expensive than ammunition in the new .17 Rimfire calibers. Since many of the rifles that chamber the .22 WMR use tubular magazines, bullet noses are generally flat or blunt to allow smooth feeding. While a pointed bullet is not going to rest against the primer of the round in front of it (like in a centerfire cartridge), a pointed bullet could still hang on the manufacturer's stamp, which is found in the middle of the base of the cartridge. .22 Long Rifle - Subsonic Hollowpoint (left), Standard Velocity (Centre), Hyper-Velocity Stinger Hollowpoint (Right). ... .17 Rimfire refers to a . ... A centerfire cartridge is a cartridge in which the primer is located in the center of the cartridge case head. ...

Due to the limited selection of commercial ammunition, the .22 WMR was the case used by a small but dedicated group of wildcatters for handloading high performance rimfire ammunition. Generally these loads would use more aerodymamic pointed bullets, the same type used by .22 caliber centerfire cartridges. While these bullets were often heavier than standard .22 WMR bullets, the sharp nose and tapered tail retained velocity better, and delivered more energy downrange. Other wildcatters would neck the .22 WMR down to smaller calibers, such as .20 (5 mm) and .17 (4.5 mm) or even smaller, in an attempt to get maximum velocity and the flattest possible trajectory (see external ballistics). A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. ... Handloading is the process used to create firearm cartridges by hand versus those put together en masse and sold commercially, generally in packages of 6 to 50. ... A centerfire cartridge is a cartridge in which the primer is located in the center of the cartridge case head. ... External ballistics is the part of ballistics tht refers to the behavior of a bullet after it exits the barrel and before it hits the target. ...

The .22 WMR was also the basis for the first new commercial rimfire of the 21st century, the .17 HMR. The .17 HMR, with its tiny .172 caliber (4.5 mm) bullet, offers much higher velocities and a flatter trajectory than the .22 WMR, though the .22 WMR still offers better penetration with its heavier bullet (see terminal ballistics). . ... Terminal ballistics, a sub-field of ballistics, is the study of the behavior of a projectile when it hits its target. ...

Not generally thought of as a defense cartridge, for its size it is formidable. From a handgun it will generate over a 42% one shot stop ratio on human targets, according to Marshall and Sanow). From a rifle, of which many models are available, it develops muzzle energy equal to that of the subsonic 9mm Luger loadings. The new 5.7 x 28 mm SS196SR round chambered in the FN P90 personal defense weapon produces very similar ballistics to the .22 WMR rifle, firing a 40 grain bullet at 1800 f/s. Subsonic has two possible meanings: A speed lower than the speed of sound is called subsonic. ... ball and hollowpoint 9mm Luger rounds are popular handgun ammunition. ... The P90 is a submachine gun developed and manufactured by Fabrique Nationale de Herstal (FN Herstal). ... A PDW or personal defense weapon is a compact firearm, smaller than an assault rifle or a full size submachine gun, but more powerful and flexible than a normal pistol. ...

See also

References

Bibliography

External links

• Chuck Hawk's page on the .22 WMR
• The .22 WMR TODAY, Guns Magazine, June, 2001 by C. Rodney James
• Three .22 WMR Loads From Remington, Handguns Magazine, by Phil W. Johnston
• Reloading Techniques: .22 Win. Magnum Rimfire, Performance Shooter, April 1996