.38-40 is a centerfire cartridge that was introduced by Winchester in 1874 for use in their Model 1873 lever-action rifle. It is also known as the .38 WCF (Winchester Center Fire) or .38-40 Winchester.
The .38-40 cartridge is typically loaded with a 180-grain bullet and has a muzzle velocity of around 1,100 to 1,200 feet per second. It was originally designed as a dual-purpose cartridge, suitable for both hunting and self-defense.
The .38-40 cartridge saw extensive use in the late 19th and early 20th centuries, particularly in lever-action rifles and revolvers. It was widely used for hunting and small game shooting, and also saw use as a self-defense cartridge, particularly among law enforcement and civilians who needed a versatile, multi-purpose firearm.
Today, the .38-40 cartridge is less commonly used, as more powerful cartridges have become more readily available. However, it is still occasionally used for target shooting, historical reenactments, and other specialized applications.
It is important to note that the .38-40 cartridge is not interchangeable with the more common .38 Special cartridge, as they have different case lengths and diameters. Attempting to use .38-40 ammunition in a .38 Special revolver, or vice versa, can result in malfunction or damage to the firearm.