The hypervelocity .270 — driving bullets at speeds Jack O'Connor's beloved .270 Winchester couldn't approach. An early Weatherby creation that outlasted the man himself.
Type: Rifle
Introduced: 1943, United States
Parent case: .375 H&H Magnum
Standardization: SAAMI
Bullet diameter: 0.277" (7.03 mm)
Case length: 2.549" (64.74 mm)
Overall length: 3.295" (83.69 mm)
Max pressure: 65,000 PSI
Rim type: Belted
Primer: Large Rifle Magnum
Typical twist rate: 1:10
Muzzle velocity: 3150–3550 fps
Muzzle energy: 2200–3746 ft-lbs
Effective range: 600 yd
Common bullet weights: 100, 130, 140, 150 gr
Primary use: Hunting, Long Range
Production status: Active
Also known as: .270 Wby Mag
History: One of Weatherby's original cartridges. The great gun writer Jack O'Connor championed the standard .270 Winchester; Weatherby's magnum version outperformed it by 400-500 fps. Their philosophical battle — O'Connor favoring light loads, Weatherby favoring maximum velocity — defined American hunting cartridge debate for 30 years.
Notable firearms: Weatherby Mark V, Weatherby Vanguard
Similar cartridges: .270 Winchester, .270 WSM, 7mm Remington Magnum