| .375 Winchester | |
| Origin: | United States |
| Type: | Rifle |
| Design Date: | 1978 |
| Manufacturer: | Winchester |
| Production Date: | 1978–present |
| Parent: | .38-55 Winchester |
| Case Type: | Rimmed, straight |
| Bullet: | .375 |
| Land: | .366 |
| Land Ref: | [1] |
| Neck: | .400 |
| Base: | .420 |
| Rim Dia: | .506 |
| Rim Thick: | .063 |
| Case Length: | 2.020 |
| Length: | 2.560 |
| Pressure Method: | CIP |
| Max Pressure: | 55000 |
| Max Cup: | 52,000[2] |
| Bw1: | 200 |
| Btype1: | JFP |
| Vel1: | 2223 |
| En1: | 2194.12 |
| Bw2: | 200 |
| Btype2: | JFP |
| Vel2: | 2419 |
| En2: | 2598.09 |
| Bw3: | 220 |
| Btype3: | JFP |
| Vel3: | 2029 |
| En3: | 2010.66 |
| Bw4: | 220 |
| Btype4: | JFP |
| Vel4: | 2236 |
| En4: | 2441.85 |
| Balsrc: | Hodgdon Online Reloading Data |
The .375 Winchester / 9.5x51mmR is a modernized version of the .38-55 Winchester, a black powder cartridge from 1884. It was introduced in 1978 along with the Winchester Model 94 “Big Bore” lever action rifle, which was in production from 1978 until 1986.[3]
Though very similar in appearance to the .38-55 Winchester parent cartridge, the .375 Winchester cartridge has a shorter case length and operates at a higher chamber pressure of 52,000 CUP or 55,000 psi (380 MPa), compared to the .38-55 Winchester cartridge which has a longer case length and operates at a lower chamber pressure of 30,000 CUP or 35,000 psi (240 MPa).
The most commonly used bullet weights for the .375 Winchester are between 180 gr to 260 gr (11.7 g to 16.9 g) and has been used on a variety of medium to large game species such as whitetail, pronghorn, caribou, elk, moose, black bear, and brown bear.[4]