The 5.7x28mm cartridge, initially designed for the FN P90 personal defense weapon and FN Five-seven pistol, has gained notoriety for its unique capabilities, particularly its armor-piercing potential. While not suitable for all applications, the 5.7x28mm armor-piercing round offers a distinct niche within the world of small arms ammunition. This article delves into the specifics of these rounds, examining their design, ballistics, effectiveness, and legal considerations.
Understanding the 5.7x28mm Cartridge
The 5.7x28mm round's small caliber and high velocity are its defining characteristics. This combination results in a flat trajectory and significant penetration, making it effective at longer ranges compared to larger-caliber handgun rounds. The cartridge's high velocity is achieved through a relatively long case and the use of a lightweight projectile. This lightweight projectile, however, also contributes to its limitations, as discussed later.
Key Features of the 5.7x28mm Round:
- High Velocity: Typically exceeding 2,600 feet per second (fps), resulting in a flat trajectory.
- Lightweight Projectile: Contributing to high velocity but impacting stopping power.
- Small Caliber: Reduces recoil and allows for higher magazine capacities.
- Penetration Capabilities: Effective against soft body armor and some forms of harder body armor depending on the round.
Types of 5.7x28mm Armor-Piercing Rounds
While the specific designs vary by manufacturer, 5.7x28mm armor-piercing rounds generally share common features. The primary objective is to penetrate body armor while maintaining sufficient energy to inflict injury on the target.
SS190: The Original Armor Piercing Round
The SS190 is perhaps the most well-known 5.7x28mm armor-piercing round. Designed with a hardened core, it's capable of penetrating various levels of soft body armor. However, its effectiveness against harder, ceramic plates is limited. It’s important to note that the SS190 is often considered controversial due to its potential to penetrate soft body armor commonly worn by law enforcement.
Other Armor-Piercing Ammunition
Several manufacturers produce variations on the armor-piercing theme. These may use different core materials, jacket compositions, and designs to optimize penetration or enhance other aspects of ballistics. These differences can slightly affect the performance of these rounds.
Ballistics and Effectiveness of 5.7x28mm Armor-Piercing Rounds
The effectiveness of 5.7x28mm armor-piercing rounds is heavily dependent on the type of armor it encounters. While capable of penetrating soft body armor, its performance against hard plates is drastically reduced.
Penetration Testing Data
- Soft Body Armor: Consistently penetrates Level IIA and II soft body armor. Performance against higher levels of soft armor is variable and depends on the specific armor and the round's condition.
- Hard Body Armor: Penetration is significantly reduced against Level III and IV hard armor. Often, rounds will ricochet or fail to penetrate entirely.
(Insert Table Here: A table summarizing penetration test results for different levels of body armor using various 5.7x28mm armor-piercing rounds. Source data should be cited.)
Legal Considerations and Restrictions
Due to the potential for these rounds to penetrate body armor, several jurisdictions have placed restrictions or outright bans on the civilian ownership or sale of 5.7x28mm armor-piercing ammunition. It is crucial to be aware of and comply with all local, state, and federal laws concerning the possession and use of this type of ammunition.
Conclusion: The Niche of the 5.7x28mm Armor Piercing Round
The 5.7x28mm armor-piercing round occupies a specialized niche in the world of small arms ammunition. Its high velocity and ability to penetrate soft body armor make it an effective tool in certain situations, particularly where close-quarters combat is involved. However, its limitations against harder armor and the legal restrictions surrounding its ownership require careful consideration before use. Always prioritize safety and adhere to all relevant laws and regulations.