5 mm Remington Rimfire Magnum

The 5 mm Remington Rimfire Magnum is an obsolete bottlenecked rimfire cartridge introduced by Remington Arms Company in 1969. Remington chambered it in a pair of bolt-action rifles, the Model 591 and Model 592, but the round never became very popular, and the rifles were discontinued in 1973. The ammo was discontinued in 1982. About 52,000 rifles were sold during its brief production run. As of 2008, Aguila, a Mexican ammunition company, is producing 5mm Remington Magnum ammunition.

Design
Remington designed a new case that was very similar to the older .22 Mag, but stronger to handle the higher pressure of the 5 mm at 33,000 PSI. It uses a 5mm (.20 caliber) bullet that measure 0.2045 in, the same as the more recent .204 Ruger cartridge.

For a brief time, Thompson Center Arms offered firearms in 5 mm Mag. From 1982 until 2008, no ammunition manufacturers manufactured rounds for this cartridge, but some firearms manufacturers are creating conversion kits to allow the existing 5 mm guns to shoot other more-common cartridges.

At the 2008 SHOT show, Taurus International introduced the first handgun chambered for the 5mm Remington Magnum rimfire. Concurrent with the announcement from Taurus, Aguila Ammunition announced they would begin producing 5mm RMR ammunition in 2008.

As of May 2011, Taurus has not yet imported nor produced their Tracker in 5mm Remington rimfire. They had stated that it will be manufactured and imported pending production demand in the second half of 2010.

Performance
The 5 mm Mag offers higher velocity than the .22 WMR and more energy than either the .22 WMR or the later .17 HMR. It offers decent performance on small-game and for varmint hunting. The Aguila/Centurion 5mm Magnum ammunition comes in two offerings: the original "White Box" with a 30 grain hp, as well as a "Varmint" round with a 30 grain jacketed hp.

Centerfire Conversion to 5mm Craig
When Remington discontinued production of 5mm RRM ammunition, owners of Remington 591 and 592 rifles were left with excellent rifles but no ammunition for them. Mike Craig of Seattle, WA, in 1994 began work on a centerfire conversion of the 5mm RRM, the 5mm Craig. His company, Certech, also performed conversions of 5mm rifles from rimfire to centerfire by altering the bolt and installing a new firing pin. The result was that owners of these rifles could once again enjoy shooting them. Mike has since sold all the rights to the 5mm Craig to Eagle View Arms of Shelton, WA.