British cartridge for Martini-Henry pattern rifles converted from .577/450. The .500-450 family covered several variants for different barrel specifications.
Type: Rifle
Introduced: 1880, United Kingdom
Parent case: .577/450 Martini-Henry
Standardization: Obsolete / Non-standard
Bullet diameter: 0.451" (11.45 mm)
Max pressure: 18,000 PSI
Rim type: Rimmed
Primer: Large Rifle
Typical twist rate: 1:22
Muzzle velocity: 1200–1350 fps
Muzzle energy: 1534–1941 ft-lbs
Effective range: 150 yd
Common bullet weights: 480 gr
Primary use: military, hunting
Production status: Obsolete
Also known as: .500-450 Musket · 500-450 No.2 Musket · .500-450
History: A British musket conversion cartridge from the 1860s, designed for .577-bore military rifles being converted from muzzle-loading to breech-loading. Part of the emergency conversion program that outfitted British colonial troops with repeating arms more quickly than building new rifles would allow.