The cartridge that almost replaced .30-06. Lighter, flatter-shooting, and ergonomically superior — but General Douglas MacArthur personally killed its adoption.
Type: Rifle
Introduced: 1923, United States
Parent case: None
Standardization: SAAMI
Bullet diameter: 0.284" (7.21 mm)
Case length: 2" (50.8 mm)
Overall length: 2.85" (72.39 mm)
Max pressure: 50,000 PSI
Rim type: Rimless
Primer: Large Rifle
Typical twist rate: 1:10
Muzzle velocity: 2550–2700 fps
Muzzle energy: 1804–2190 ft-lbs
Effective range: 600 yd
Common bullet weights: 125, 135 gr
Primary use: Military (Historical)
Production status: Active
Also known as: 7x51mm Pedersen
History: John Pedersen designed both the cartridge and the semi-automatic rifle to fire it. Army trials from 1925-1932 showed it outperformed .30-06 in many respects. The Army's Ordnance Board recommended adoption. General MacArthur overruled the recommendation, insisting on full-power .30-06. The Garand was redesigned for .30-06 instead.
Notable firearms: Pedersen rifle (prototype), T1 Garand prototype
Military use: {"country":"Proposed for U.S. Army — rejected 1932","years":""}
Similar cartridges: 7mm-08 Remington, .280 British