.33 Win.

The .33 Winchester, also known as the .33 WCF (Winchester Center Fire), is a centerfire rifle cartridge developed by the Winchester Repeating Arms Company in the early 1900s. It was designed for use in lever-action rifles and was based on the same case as the .32 Winchester Special, but necked up to accept a larger, .338-inch bullet.

The .33 Winchester cartridge typically fires a 200- or 225-grain bullet at a muzzle velocity of around 2,100 to 2,300 feet per second, delivering moderate energy and stopping power at medium ranges. It was designed as a hunting cartridge for use on medium to large game such as deer and elk, and it gained a reputation as an effective and versatile cartridge for hunters.

However, the .33 Winchester was not as popular as some of Winchester's other cartridges, such as the .30-30 and .38-55, and it was eventually discontinued in the mid-1930s. Nonetheless, it remains a historical and collectible cartridge, and is occasionally still used for hunting by enthusiasts of classic lever-action rifles.