|5mm Remington Rimfire Magnum|
|Place of origin||United States|
|Designer||Remington Arms Company|
|Case type||Rimfire, bottleneck|
|Bullet diameter||.204 in (5.2 mm)|
|Neck diameter||.225 in (5.7 mm)|
|Shoulder diameter||.259 in (6.6 mm)|
|Base diameter||.259 in (6.6 mm)|
|Rim diameter||.325 in (8.3 mm)|
|Rim thickness||.050 in (1.3 mm)|
|Case length||1.020 in (25.9 mm)|
|Overall length||1.30 in (33 mm)|
|Maximum pressure||33,000 psi (230 MPa)|
|Source(s): "Cartridges of the World",|
The 5mm Remington Rimfire Magnum or 5mm RFM is a 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 1974. About 52,000 rifles and 30,000 barrels for the T/C Contender pistol were sold during its brief production run. Remington discontinued the cartridge itself in 1982, leaving owners with no source of ammunition.
From 1982 until 2008, no ammunition manufacturers manufactured rounds for this cartridge. Some firearms manufacturers even created conversion kits to allow the existing 5 mm guns to shoot other more-common cartridges.
At the 2008 SHOT Show, Aguila Ammunition announced it would reintroduce the cartridge and begin commercial production of 5mm RFM ammunition. Until 2019, the cartridges were sold in the United States of America under the Centurion brand. In 2019, Aguila Ammunition announced the company now offered two 5mm RFM loads: one with a semi-jacketed hollow point bullet and a second with a full jacketed hollow point bullet. Both loads use a 30 grain projectile and have a muzzle velocity of 2,300 fps.
The 5 mm RRM offers higher velocity than the .22 WMR and more energy than both the .22 WMR and the later .17 HMR. It offers improved performance on small-game and for varmint hunting, along with excellent accuracy.
|38||grain||5mm RFM||Remington||C.L. HP||Velocity||2100||1839||1605||1401||1231||ft/s|
|38||grain||5mm RFM||Remington||C.L. HP||Energy||372||285||217||166||128||ft·lbf|
|Trajectory (100 yards zero)|
|38||grain||5mm RFM||Remington||C.L. HP||Trajectory||0||+0.5||0||-3.9||in.|
When Remington discontinued production of 5mm RFM ammunition, owners of Remington 591 and 592 rifles were left with excellent rifles but no ammunition for them. Mike Craig, in 1994, in Seattle, began work on a centerfire conversion of the 5mm RFM, the 5mm Craig. His company, Certech, also performed conversions of 5 mm rifles from rimfire to centerfire by altering the bolts and installing new firing pins, restoring them to use. Craig has since sold all the rights to the 5mm Craig to Eagle View Arms of Shelton, Washington.
At the 2008 SHOT show, Taurus International introduced the first handgun chambered for the 5mm Remington Magnum Rimfire.