The 5.7x28mm cartridge, often associated with FN Herstal's P90 personal defense weapon and Five-seveN pistol, is a unique and controversial round. Its performance characteristics, applications, and overall effectiveness spark considerable debate among firearms enthusiasts and experts. This guide delves into the specifics of 5.7x28mm ammunition, exploring its design, ballistics, uses, and limitations.
Ballistics and Design Features of 5.7x28mm
The 5.7x28mm round distinguishes itself through its small caliber and high velocity. This combination delivers a flat trajectory and significant penetration capabilities, particularly against soft targets. The cartridge's design incorporates several key features:
- High Velocity: Achieving exceptionally high muzzle velocities is a defining characteristic. This contributes to its extended effective range compared to larger calibers at closer ranges.
- Small Caliber: The small diameter of the projectile (5.7mm) allows for high magazine capacity in compact firearms. This is a critical factor for personal defense weapons (PDWs) like the P90.
- Lightweight Projectile: The relatively light bullet weight minimizes recoil, enhancing controllability, especially during rapid firing.
- Penetration Capabilities: While effective against soft targets, its penetration against harder materials, like body armor, varies greatly depending on the projectile type (SS190, SS197, etc.).
Types of 5.7x28mm Ammunition:
Several types of 5.7x28mm ammunition cater to different needs:
- SS190: This full metal jacket (FMJ) round is primarily designed for penetration, particularly against soft targets. Its performance against body armor is debated, with some rounds penetrating and others failing to do so.
- SS195 LF: This less lethal round is designed to minimize penetration while maximizing incapacitation. It's considered a suitable alternative for situations where lethal force is undesirable.
- SS197 SR: A special purpose round designed for enhanced penetration against body armor. This round is less frequently encountered due to legal restrictions and ethical concerns in some jurisdictions.
Applications and Suitability of 5.7x28mm
The 5.7x28mm cartridge finds its niche in specific applications:
- Personal Defense Weapons (PDWs): The high capacity magazines and manageable recoil make it ideal for PDWs intended for close-quarters combat and personal protection.
- Law Enforcement: Some law enforcement agencies utilize the 5.7x28mm for specialized units requiring high-capacity, lightweight weapons with significant penetration potential.
- Sporting and Target Shooting: Although less common, the cartridge is used in some competitive shooting sports, appreciating its accuracy and ease of handling.
Limitations and Criticisms of 5.7x28mm
Despite its advantages, the 5.7x28mm cartridge isn't without its drawbacks:
- Limited Stopping Power: The relatively small projectile size and weight can result in less stopping power compared to larger calibers, potentially requiring multiple hits for incapacitation.
- Armor Penetration Concerns: The level of penetration against body armor is highly variable depending on the round type and the armor's construction. This uncertainty is a significant concern for law enforcement and military applications.
- Cost: 5.7x28mm ammunition tends to be more expensive than other commonly used handgun and rifle calibers.
Conclusion:
The 5.7x28mm cartridge presents a unique blend of advantages and disadvantages. Its high velocity and flat trajectory are beneficial in close-quarters combat, and its compact size allows for high magazine capacity. However, concerns remain regarding its stopping power and inconsistent armor penetration. Ultimately, the suitability of this cartridge depends heavily on the specific application and user requirements. Further research and independent testing remain essential for a comprehensive understanding of its capabilities and limitations.
