.45 Win. Mag.

The .45 Winchester Magnum is a centerfire handgun cartridge that was developed by Winchester in the early 1970s. It is based on the .45 Colt cartridge, but is loaded to much higher pressures and velocities, making it a much more powerful cartridge.

The .45 Win Mag has a bullet diameter of .452 inches (11.5 mm) and a case length of 1.222 inches (31.0 mm). It is typically loaded with bullets weighing between 225 and 260 grains (14.6 to 16.8 g), and has a typical muzzle velocity of around 1,300 to 1,600 feet per second (400 to 490 m/s) and a muzzle energy of around 1,000 to 1,200 foot-pounds (1,360 to 1,630 J).

The .45 Win Mag is primarily used for hunting, particularly for larger game such as deer and bear. It is also used for self-defense and some competitive shooting events. However, the cartridge has not achieved the same level of popularity as some other handgun cartridges, and ammunition can be more difficult to find than for more established cartridges such as the .45 ACP or 9mm.