U.S. Military Tests Low-Cost Drone Defenses After 378 Border Incursions in 30 Days.

The U.S. military detected 378 drone incursions along the U.S.-Mexico border in just 30 days, underscoring the growing challenge posed by small unmanned aircraft used for surveillance and cross-border activity. In response, U.S. forces are accelerating tests of layered counter-UAS defenses combining radars, interceptor drones and automated gun systems such as the Bullfrog M240 to detect, track and defeat low-cost aerial threats.

The activity is driving a broader effort to build a counter-drone architecture suited to homeland operations, where commanders must protect forces and critical areas without relying on expensive surface-to-air missiles or creating unnecessary risks near populated zones and civilian airspace. Falcon Peak 26.2 at Yuma Proving Ground in Arizona provided a test environment for evaluating how different sensors and defeat systems can work together against the same class of small drones seen along the southern border.

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The ACS Bullfrog M240 counter-UAS weapon system fires at drone targets during Exercise Falcon Peak at Cibola Range, Joint Experimental Range Complex 2, Yuma Proving Ground, Arizona, on September 9, 2026. (Picture source: U.S. Department of War/Defense)

The operational challenge begins with detection. Small commercial drones can fly low, move slowly, and have limited radar signatures, making them harder to classify than conventional aircraft or missiles. U.S. forces therefore need persistent sensors that can establish tracks early enough for operators to determine whether an unmanned aircraft is benign, suspicious, or potentially hostile.

Once a drone is detected, the next step is to maintain the track, identify the aircraft, and assess its behavior before selecting an appropriate means of neutralization. That sequence- detect, track, identify, select a defeat option, and engage- is central to the layered counter-UAS approach now being tested, because no single weapon or sensor can address every small-drone scenario.

The Bullfrog M240 is one of the more notable kinetic systems involved in the effort. Developed by Allen Control Systems, the remotely operated weapon uses an M240 7.62x51 mm machine gun combined with automated target tracking and fire-control technology intended to engage small unmanned aircraft at short range.

During Falcon Peak, the Bullfrog was evaluated as a counter-UAS test system rather than used operationally against cartel drones. That distinction matters: the exercise examined how the weapon could contribute to border defense, but available information does not show that Bullfrog engaged real criminal unmanned aircraft during the event.

Its potential advantage lies in cost and sustainability. Firing machine-gun ammunition against an inexpensive quadcopter can offer a far more favorable cost-per-interception ratio than using a sophisticated air-defense missile, particularly if incursions occur repeatedly and in large numbers. The same logic applies to interceptor drones tested alongside gun-based systems, which can provide another comparatively low-cost way to physically stop a small UAS.

No single defeat mechanism suits every engagement. Ballistic weapons may create unacceptable risks in some locations, while electronic warfare can be constrained by spectrum conditions, drone autonomy, or concerns about interference with civilian systems. Falcon Peak therefore emphasized a layered defense in which sensors establish the track, command-and-control systems support identification, and operators select between kinetic interceptors, gun systems, electronic effects, or other countermeasures according to the environment.

This low-collateral defeat requirement matters especially along the southern border. Counter-UAS systems may need to operate near roads, infrastructure, civilian communities, and controlled airspace, where destroying a drone is only part of the problem. Commanders must also consider where debris will fall, whether a projectile can be fired safely, and whether the neutralization method could affect civilian communications or aircraft.

The 378 incursions detected in one month illustrate the scale of the surveillance challenge. Many of the aircraft involved are believed to be commercially available drones equipped with cameras and used to monitor security activity, observe patrol routes, or support smuggling operations, creating a threat profile very different from traditional air defense.

The target is usually not a high-speed aircraft or missile, but a small, cheap, and replaceable unmanned aircraft whose value may be measured in hundreds or thousands of dollars. For U.S. forces, that creates an unfavorable economic problem if every drone requires a high-end interceptor, making cheaper and reusable defeat options increasingly important for sustained operations.

The border mission is therefore becoming a useful test case for the wider counter-UAS problem. It provides a real operating environment in which U.S. forces face persistent small-drone activity while evaluating combinations of sensors, weapons, and command systems designed to reduce the cost of each engagement.

Lessons from the southern border also have relevance beyond homeland defense. The war in Ukraine has shown how inexpensive drones can be used in large numbers for reconnaissance, target acquisition, attack, and battlefield surveillance, forcing militaries to rethink the economics of air defense and how many low-cost interceptors they can sustain in prolonged operations.

A layered system combining radar, passive sensors, interceptor drones, electronic effects and automated guns could give U.S. units more options at different ranges and against different target types. The key is not simply to shoot down more drones, but to match each threat with the cheapest, most effective, and operationally acceptable means of defeat.

That makes the Bullfrog M240 significantly less as a standalone weapon than as one layer within a broader counter-UAS architecture. Its potential role is to provide a lower-cost kinetic option for short-range engagements when other defeat methods are unavailable, unsuitable, or unnecessarily expensive.

The broader objective is to create a defensive chain that remains effective even when drone activity becomes frequent. Detecting 378 incursions in 30 days shows why the U.S. military is increasingly focused on systems that can protect forces at scale without turning every small-drone engagement into a high-cost air-defense event.

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Written by Alain Servaes – Chief Editor, Army Recognition Group
Alain Servaes is a former infantry non-commissioned officer and the founder of Army Recognition. With over 20 years in defense journalism, he provides expert analysis on military equipment, NATO operations, and the global defense industry.