Short-action 7mm cartridge with a rebated rim, fitting a .473" bolt face despite a larger .500" base. Offers near-7mm Remington Magnum performance in a short action with excellent case capacity for heavy, high-BC bullets.
Type: Rifle
Introduced: 1963, United States
Parent case: None
Standardization: SAAMI
Bullet diameter: 0.284" (7.21 mm)
Case length: 2.17" (55.12 mm)
Overall length: 2.8" (71.12 mm)
Max pressure: 56,000 PSI
Rim type: Rebated
Primer: Large Rifle
Typical twist rate: 1:10
Muzzle velocity: 2800–3000 fps
Muzzle energy: 2435–2900 ft-lbs
Effective range: 500 yd
Common bullet weights: 140, 150, 160, 168, 175 gr
Primary use: Hunting, Target, Competition
Production status: Active
Also known as: 7mm Winchester · 7x51mm
History: Introduced by Winchester in 1963 for the Model 88 lever-action and Model 100 semi-automatic. The rebated rim — smaller than the case body — was an unusual engineering choice that allowed the large-capacity case to fit standard bolt faces. Despite good ballistics, commercial success was limited: the 7mm Remington Magnum debuted the same year and captured the market. Reloaders rediscovered the .284…
Notable firearms: Winchester Model 88, Winchester Model 100, Savage 110 (custom)
Similar cartridges: 7mm-08 Remington, 7mm Remington Magnum, 7x57mm Mauser