Marine Corps Integrating Counter-Drone Ammunition Into Virtual Marksmanship Training

The U.S. Marine Corps is bringing a new class of small arms ammunition into its virtual training environment. Drone Round, a developer of counter-unmanned aircraft system munitions, announced that its 5.56x45mm L Variant cartridge has been integrated into the Marine Corps' Indoor Simulated Marksmanship Trainer, or ISMT — a widespread virtual small arms training system produced by InVeris and currently installed at bases across the Corps.

The integration addresses a training gap that emerged as counter-drone skills became a requirement for general-purpose forces. The L Variant, which fragments into five separate projectiles after firing to improve hit probability against small aerial targets, has been purchased by the Marine Corps in significant quantities: 400,000 rounds to date, with an additional one million rounds budgeted in fiscal year 2027 beginning October 1. Live rounds are being distributed to Marine Expeditionary Force commands, with ammunition supply point deliveries expected to finish this month.

Why Training Needed to Catch Up

Counter-UAS engagements demand a different skill set than conventional rifle qualification. Operators must detect and track fast-moving aerial threats, often at close range, and decide when to engage with little hesitation. Live rounds issued to the field are earmarked for operational use — not for building familiarization. That created a genuine training shortfall as the Corps pushed counter-drone skills deeper into the force.

Marines with the 3rd Marine Aircraft Wing began encountering small UAS threats during Service Level Training Exercise 4-26 at Marine Corps Air Ground Combat Center Twentynine Palms in July 2026, where they practiced engagements alongside electronic warfare techniques. The ISMT integration now lets Marines across the Corps practice those same engagement sequences — detect, track, decide, fire — in a simulated environment, on the same systems already standing in their barracks buildings.

"The round was built so a Marine could use the rifle already in their hands, and the training has to work the same way, on the simulators already in the building," said Kirk Fernandez, co-founder and CEO of Drone Round. "Getting the virtual capability out at the same time as the ammunition means a Marine can practice the engagement before the moment they need it."

The Technology: L Variant at a Glance

The 5.56mm L Variant is designed to engage aerial targets at ranges up to 100 meters. It requires no modification to standard NATO-compliant 5.56mm weapons and is compatible with both full-auto fire and suppressors — a relevant consideration for Marines engaging small drones in varied operational environments. The multi-projectile fragmentation pattern increases the probability of hitting small, maneuvering targets that conventional ball ammunition struggles to track.

Drone Round has also developed L and K Variants in 7.62x51mm NATO, expanding the counter-UAS family across heavier weapon systems. The Army's XVIII Airborne Corps has incorporated Drone Round ammunition into its training curriculum since April 2026.

What It Means for the Force

The partnership with InVeris reflects a broader shift in how the Marine Corps is building counter-drone readiness at scale. Rather than standing up a separate training pipeline, the service is layering C-UAS skills onto the existing ISMT infrastructure — a COTS platform that InVeris will continue expanding with new scenarios and threat profiles as both the UAS threat and Marine tactics evolve.

With 200-plus ISMT systems across the force and a million-round procurement on the horizon, the L Variant is positioned to become a standard part of the individual Marine's training cycle — not just a specialty round for dedicated counter-drone operators.

Source: Soldier Systems Daily