| .50 Remington Navy | |
| Origin: | United States |
| Type: | Handgun |
| Production Date: | 1865–1866 |
| Case Type: | Rimmed, straight |
| Bullet: | .510 |
| Neck: | .535 |
| Shoulder: | .535 |
| Base: | .562 |
| Rim Dia: | .642 |
| Case Length: | .860 |
| Length: | 1.28 |
| Primer: | Rimfire |
| Bw1: | 290 |
| Vel1: | 600 |
| En1: | 234 |
| Balsrc: | Barnes & Amber 1972 |
The .50 Remington Navy / 13x21mmRF is a 0.51NaN1 American rimfire handgun cartridge.
Introduced for the Remington Navy single-shot, rolling block pistol in 1865, the low-velocity round loaded a 290gr bullet over 23gr of black powder.
The rimfire version was replaced in 1866 by a centerfire equivalent. A Boxer-primed version remained commercially available until World War I.
The power of the .50 Remington was less than average, but the heavy bullet, even at comparatively low velocity, made it "a rather potent handgun round".