57x28mm

57x28mm refers to a specific cartridge size used in firearms. The first number, 57, indicates the approximate diameter of the bullet in millimeters. The second number, 28, denotes the approximate length of the cartridge case in millimeters. This particular cartridge size is associated with specific firearm models. For instance, the 57x28mm is the designation for the 5.7x28mm FN cartridge, developed by FN Herstal. This ammunition is primarily used in personal defense weapons and submachine guns, such as the FN P90 and the FN Five-seveN pistol. The 5.7x28mm round is known for its relatively high velocity, flat trajectory, and reduced recoil compared to traditional pistol cartridges. Its small diameter and bottlenecked case design contribute to its unique ballistic characteristics. Ammunition for the 57x28mm is available in various loadings, including armor-piercing and standard ball rounds, designed for different tactical applications. The development of this cartridge was driven by the need for a compact and effective firearm system suitable for special forces and law enforcement.