.257 Roberts
1934 · Ned H. Roberts · 1 firearm in catalog
Also known as: .257 Roberts, 257 Roberts, .25 Roberts
Cartridge specifications
| Bullet Diameter | 6.53 mm (0.257") |
| Neck Diameter | 7.32 mm (0.288") |
| Base Diameter | 11.94 mm (0.470") |
| Case Length | 56.77 mm (2.235") |
| Overall Length | 71.12 mm (2.800") |
| Max Pressure | 379 MPa (54,000 psi) |
| Typical Bullet Weight | 7.45 g (115 gr) |
| Typical Muzzle Velocity | 884 m/s (2900 fps) |
| Typical Muzzle Energy | 2912 J (2148 ft·lbf) |
| Primer Type | Large Rifle |
| Cartridge Type | Rimless |
| Introduced | 1934 |
Firearms chambered in .257 Roberts
- Remington Model 722 — Remington Arms · Rifle · 1948