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 it 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] This ammunition-related article is a stub.