.256 Gibbs Magnum

Photo coming soon: side view on a transparent background, with author and license.

Key specs

Type: Rifle
Origin: United Kingdom
Designer: George Gibbs of Bristol
Introduced: 1913
Case type: rimless, bottleneck
Bullet diameter: 6.71 mm
Case length: 55.12 mm
Overall length: 78.49 mm
Typical bullet: 145 gr
Typical velocity: 793 m/s
Typical energy: 2,953 J
Parent case: 6.5×57mm Mauser

Sources

Wikipedia: .256 Gibbs Magnum, Wikipedia