Extremely fast and flat-shooting magnum. Roy Weatherby's favorite cartridge. Devastating on deer-sized game at long range. Barrel burner.
Type: Rifle
Introduced: 1944, United States
Parent case: .375 H&H Magnum
Standardization: SAAMI
Bullet diameter: 0.257" (6.53 mm)
Case length: 2.549" (64.74 mm)
Overall length: 3.17" (80.52 mm)
Max pressure: 65,000 PSI
Rim type: Belted
Primer: Large Rifle Magnum
Typical twist rate: 1:10
Muzzle velocity: 3400–3825 fps
Muzzle energy: 2500–3300 ft-lbs
Effective range: 500 yd
Common bullet weights: 75, 87, 100, 110, 120 gr
Primary use: Hunting, Varmint
Production status: Active
Also known as: .257 Wby Mag
History: Developed by Roy Weatherby in 1944 as his first commercial magnum cartridge. Based on blown-out .375 H&H case necked to .257. Weatherby's personal favorite cartridge. Delivers high muzzle velocity and a flat trajectory. Popular with western hunters and long-range shooters. Heavy recoil for a .25 caliber and significant barrel wear, but dramatic performance.
Notable firearms: Weatherby Mark V, Weatherby Vanguard, Custom rifles
Similar cartridges: .25-06 Remington, 6.5-300 Weatherby