Marines Seek New Armor-Piercing 5.56mm Rounds

New Military Rifle Round


The current 5.56mm Enhanced Performance Rounds employed by the Army and Marine Corps are, as reported by military officials, no longer powerful enough to penetrate body armor plates used by enemy troops. A new military rifle round may also spell a change in standard weapon types.

The Army is implementing a replacement of the M249 squad automatic weapon and M4 carbine with weapons that are capable of firing 6.5mm case-telescoped rounds. The challenge will be implementing the change military-wide, providing the necessary training on new weapons, and ensuring that new standard weapon types won’t affect combat performance.

The Marine Corps Joins the Ammunition Experiment

Marines have, until now, remained fairly silent about outcry from Army officials for new armor-piercing ammunition rounds. However, they have quickly caught pace and are examining the possibility of using 6.5mm Creedmoor ammunition.

Decision-makers have just opted to buy more M27 5.56mm Infantry Automatic Rifles, the Marine Corps’s current preferred weapon. The planned purchase indicates that the Marines may not quite be ready to change their standard-issue arms, but they are still in agreement with the ammunitions change.

Enemy Armor Plates Have Improved

The change comes from observations that enemy body armor plates are now very similar to U.S. military-issue rifle plates, especially the Enhanced Small Arms Protective Insert, or ESAPI.

It’s a ceramic plate that goes beyond the protection of the Small Arms Protective Insert (SAPI), which stops projectiles up to and including the 9x19mm Parabellum submachine gun rounds. ESAPI adds protection from .30-06 M2 Armor-piercing bullet rounds thanks to their boron carbide construction.

Though enemy plates may not meet the exact specifications of ESAPI plates, operators have observed that modern plates compromise the stopping power of the 5.56mm round and the ability to eliminate lethal threats.

Debate is still hot over how effective the 5.56mm cartridge is in real combat. The ammunition is engineered to be lighter in weight with less recoil, which allows operators to carry about three times as much 5.56mm ammunition compared to 7.62mm ammunition. However, it has a shorter range and its stopping power is no longer armor-piercing ammunition thanks to improved enemy plates.

6.5mm Ammunition Could Be the Best Compromise

Deployed troops must carry about 50-100 pounds of non-weapons equipment when operating in combat zones. The weight of a new military rifle round could compromise a number of advantages of the 5.56mm round, such as:

  • Higher round count
  • Lighter weight in short-distance combat
  • Ease of weapons training and proficiency for inexperienced infantry

A change to 6.5mm munitions, however, may balance the need for greater stopping power with the benefits of lightweight 5.56mm rounds. Officials say that fielding new weapons that support armor-piercing 6.5mm ammunition could happen as early as 2022.


Federal Ammunition