Rimfire · SAAMI (not in current Z299)
5mm Remington Rimfire Magnum
Remington's forgotten 5mm rimfire magnum — faster than .22 WMR and with a flatter trajectory, but discontinued after only a few years.
- Caliber
- 0.204″ · 5.182 mm
- Introduced
- 1969
- Case
- Rimfire
- Primary use
- Hunting, Target
- Status
- Active
- Introduced
- 1969
- Type
- Rimfire
- Origin
- United States
- Inventor
- Remington Arms
- Manufacturer
- Remington Arms
- Standard
- SAAMI (not in current Z299)
- Status
- Active
- Availability
- Specialty
- Case capacity
- 9.4 gr H₂O
- Twist (typical)
- 1:9
- Primer
- Rimfire
- Case type
- Rimfire
- Max pressure
- 36,985 psi, CIP transducer
- Eff. range
- 150 yd
- Max range
- 2200 yd
- Recoil
- 0.14–0.16 ft·lb
- Subsonic
- Capable
Introduced by Remington Arms
Ballistics
Published velocity/energy data isn't available for 5mm Remington Rimfire Magnum.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
CIP TDCC · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 5.18 | 0.204 | ~ |
| Neck ⌀ | 5.71 | 0.225 | · |
| Shoulder ⌀ | 6.58 | 0.259 | · |
| Shoulder angle | 25° | — | |
| Base ⌀ | 6.58 | 0.259 | · |
| Rim ⌀ | 8.26 | 0.325 | ~ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.27 | 0.050 | · |
| Neck length | 4.76 | 0.187 | |
| Case length | 25.91 | 1.020 | · |
| Overall length | 32.89 | 1.295 | · |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. 5mm Remington Rimfire Magnum is highlighted below.
Missing a dimension for 5mm Remington Rimfire Magnum? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
History
Remington introduced the 5mm RFM in 1970 alongside the Model 591 and 592 bolt-action rifles. On paper it was impressive — a 38-grain bullet at 2,100 fps outpaced the .22 WMR significantly. In practice, Remington's market timing was poor: the rifles were expensive, the cartridge was proprietary, and the early 1970s were not prime years for rimfire innovation. Remington discontinued both the rifles and the ammunition in the mid-1970s, leaving thousands of 591/592 owners with firearms they couldn't feed. For decades the 5mm RFM was considered a dead end. Aguila Ammunition of Mexico began producing the cartridge in the early 2000s, restoring functionality to the surviving rifles and creating a small but dedicated collector and shooter community.
FAQs
- What twist rate does 5mm Remington Rimfire Magnum use?
- 5mm Remington Rimfire Magnum typically uses a 1:9 twist rate.
- What bullet diameter is 5mm Remington Rimfire Magnum?
- 5mm Remington Rimfire Magnum uses a 0.204″ (5.182 mm) diameter bullet.
- Is 5mm Remington Rimfire Magnum still in production?
- 5mm Remington Rimfire Magnum is active; typical availability is specialty.
- What is 5mm Remington Rimfire Magnum used for?
- 5mm Remington Rimfire Magnum is primarily used for hunting, target.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 3 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
