What is 5.7x28?

• Overview: The 5.7x28mm is a small-caliber, high-velocity centerfire cartridge designed by FN Herstal in the late 1980s and early 1990s. It was developed in conjunction with the FN P90 personal defense weapon (PDW) and the FN Five-seveN pistol.

• Purpose: The cartridge was created to offer improved performance compared to 9x19mm Parabellum, particularly against body armor. Its design prioritizes a flat trajectory, reduced recoil, and enhanced penetration.

• Design and Ballistics: The 5.7x28mm typically uses a lightweight, pointed projectile with a relatively high muzzle velocity (over 2,000 fps). This contributes to its flat trajectory and armor-piercing capabilities. Different bullet types are available, some designed for reduced ricochet or increased terminal effect.

• Advantages:

  • Armor Penetration: A key advantage is its ability to penetrate soft body armor, a significant concern for military and law enforcement.
  • Flat Trajectory: The high velocity results in a flatter trajectory, making it easier to aim at longer distances.
  • Reduced Recoil: Compared to larger cartridges, the 5.7x28mm has significantly less recoil, enabling faster follow-up shots and improved control.
  • High Capacity Magazines: The cartridge's small size allows for higher capacity magazines in firearms designed for it.

• Disadvantages:

  • Controversy: The 5.7x28mm has been the subject of controversy regarding its potential for misuse due to its armor-penetrating capabilities.
  • Cost: The 5.7x28mm ammunition tends to be more expensive than common pistol cartridges like 9mm.
  • Limited Firearm Availability: The number of firearms chambered in 5.7x28mm is smaller compared to more popular cartridges. While the FN P90 and FN Five-seveN are iconic, other options are relatively limited.

• Common Uses: Primarily used in military, law enforcement, and civilian sporting applications, particularly where armor penetration and reduced recoil are desired. It is also sometimes used for varmint hunting.