The original Winchester Big Bore cartridge — parent case for the .307 and .356 Winchester. Loaded to significantly higher pressure than the .38-55 Winchester, requiring the Big Bore 94's stronger action. An effective deer and bear cartridge at woods ranges.
Type: Rifle
Introduced: 1978, United States
Parent case: .38-55 Winchester
Standardization: SAAMI
Bullet diameter: 0.375" (9.53 mm)
Case length: 2.02" (51.31 mm)
Overall length: 2.56" (65.02 mm)
Max pressure: 52,000 PSI
Rim type: Rimmed
Primer: Large Rifle
Typical twist rate: 1:12
Muzzle velocity: 2200–2400 fps
Muzzle energy: 2150–3198 ft-lbs
Effective range: 200 yd
Common bullet weights: 200, 250 gr
Primary use: Hunting
Production status: Active
Also known as: .375 Win · 9.5x51mmR
History: Introduced in 1978 for the Winchester Model 94 Big Bore — a strengthened version of the classic Model 94 capable of handling higher-pressure cartridges. The .375 Winchester launched the Big Bore family; the .307 and .356 Winchester followed in 1982 as rimmed versions of .308 and .356. Factory ammunition remains available from Winchester. The Big Bore 94s are valued by hunters who want a powerful,…
Notable firearms: Winchester Model 94 Big Bore, Browning BLR (chambered briefly)
Similar cartridges: .38-55 Winchester, .307 Winchester, .356 Winchester