With few exceptions, time has not been kind to big game cartridges designed for close to medium range shooting. The .375 Winchester is a good example of an excellent cartridge allowed to die. It was introduced in the Winchester Model 94 in 1978 and later available in the Marlin Model 336, Savage Model 99, and Ruger No. 3 rifles. In spite of its failure to win many friends among those multitudes who hunt deer, black bear, and wild hogs, the .375 Winchester is an excellent woods cartridge. But then so is the .35 Remington, a cartridge of similar performance with a seventy year head start on Winchester's .375 cartridge. It might be of interest to note that along with the .375, Olin also developed a .40 caliber cartridge on the .30-30 case. Had the .375 become successful, we might now have a Model 94 in .400 Winchester, but since it didn't we probably seen our last new woods cartridge from Winchester. As this is written, only three .375 caliber bullets suitable for use in rifles with tubular magazines are available; the 200 grain Sierra, and 220 grain Hornady, and the 250 grain Barnes, all of flatnose form. Cast bullets up to 250 grains also work quite well in this cartridge. A number of powders do a good job here, including H335, IMR-3031, W-748, and Reloader 7. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.