Defending against Unmanned Aircraft Systems (UAS) using small arms has evolved from a “last-ditch” effort to a structured military doctrine. Recent conflicts, particularly in Ukraine, have proven that standard infantry weapons can be effective kinetic interceptors when paired with the right ammunition or optics. Militaries are increasingly integrating standard small arms (like rifles and shotguns) into layered defense strategies through new ammunition and smart optics.

1. Specialized Ammunition

Traditional ball ammunition is difficult to hit small, fast-moving drones with. New developments provide a “shotgun-like” effect from standard rifles:
• 5.56mm Anti-Drone Rounds: The U.S. has tested specialized 5.56x45mm cartridges that lose gyroscopic stability after 10–15 meters, creating a wide “cone of destruction”. At 40–50 meters, this cone expands to 60–80 cm, significantly increasing the probability of a hit on a small quadcopter.
• Programmable Airburst: Larger small arms (25mm or 40mm grenades) can use “smart” ammunition that detonates 1–3 meters before the target, creating a shrapnel cloud.
• Low Collateral Damage Technology Ammunition. Slow Shot LLC successfully demonstrated a low-collateral-damage counter-small-UAS (C-sUAS) capability during the Falcon Peak 25.2 event at Eglin Air Force Base. Slow shot is a 12 gauge shotgun round counter drone technology sUAS effector that is specifically designed for use in populated areas or near vulnerable equipment, ensuring low collateral damage and significantly reducing the risk of unintended impacts. You can see the graphic here.

2. Designated Shotgunner

The shotgun is currently considered the most cost-effective tool for close-range (point) air defense.
• Deployment: The U.S. Army recently ordered 25,000 Mossberg M590A1 shotguns specifically for the C-UAS role.
• Platforms: Highly maneuverable, magazine-fed platforms like the Genesis Arms GS-12 (a 12-gauge suppressed, fully automatic shotgun) are in final evaluations for U.S. and Australian services.
• Lessons from Ukraine: Semi-automatic shotguns (like the VEPR-12) are widely used to disrupt FPV drone operations due to their spread of pellets, which compensates for minimal training

3. Smart Optics & AI Integration

To solve the “aiming problem,” standard rifles are being upgraded with advanced fire control systems:
• SMASH 2000L: The SMASH 2000L is a lightweight, AI-powered “smart” fire control system developed by Smart Shooter to help infantrymen, including U.S. Army and Marine Corps forces, engage and destroy small unmanned aerial systems (drones) and ground targets with high precision. It attaches to standard rifles (e.g., M4), using advanced image processing to track targets and only fire when a hit is guaranteed.
• Bullfrog System: A vehicle-mounted M240 machine gun paired with AI software that can autonomously track and down drones with far higher precision than a human operator. The US Army Applications Laboratory (AAL) has awarded the Allen Control Company a $1.5 million contract to develop an integration readiness plan for its Bullfrog autonomous weapon station across five of the Army’s most widely deployed combat vehicles.

Small Arms Techniques for Engaging UAS

As discussed in the C-UAS/SUAS(1) SMARTbook, Army C-UAS doctrine addresses specific small arms techniques used in air defense that incorporate the use of volume fire and proper aiming points according to the UAS direction. If service members are trained to apply an appropriate sequence of engagement techniques for UAS based on the rules for selecting aiming points, the response will be automatic upon command. Small arms are limited to the range and destructive capability of the weapon and should be used only on low flying UAS.

The decision to fire small arms against threat UAS is the unit commander’s and is based on the situation. Considerations should at a minimum include the severity of the threat versus the potential impact of the unit’s effectiveness and the area of engagement (urban versus rural).

Soldiers that encounter UAS should consider them as a threat eligible for engagement unless positively identified as friendly. UAS can fly extremely low underneath traditional radar detection zones. They can fly very slowly with the ability to hover in place, preventing sensors from detecting them. They can also fly quickly, making it difficult to track them.

Volume Fire

Volume fire is an effective method to employ when using small arms fire against aerial threats. The key to success in engaging enemy aircraft with small arms is to put out a high volume of fire towards the immediate threat. The more bullets a unit can put in the sky, the greater the chance the enemy will fly into them. Even if these fires do not hit the enemy, throwing up a “wall of lead” in the sky can intimidate threat UAS pilots, ultimately breaking off their attack or distracting them from taking proper aim. One of the most important points about volume fire is that once the lead distance is estimated, you must aim at the estimated aiming point and fire at that single point until the aircraft has flown past that point. Maintain the aiming point, not the lead distance. Once you start firing, do not adjust your weapon.

When the decision is made to engage an aircraft with small arms, every weapon (M4, M240, M249, and M2) should be used with the goal of placing as many bullets as possible in the enemy’s flight path. That does not mean that everyone fires in some random direction. Instead, everyone selects an aiming point in front of the UAS and fires at that point. This aiming point is determined using the football field technique. When deciding to fire upon an enemy UAS, practical considerations need to be considered before engaging. An example is engaging a UAS from a range of 3 kilometers. It is important to consider the capabilities of the available weapons. Using small arms at this range is ineffective while the best possibility may be the use of the main gun on a tank or tracked vehicle. Small arms have a low probability of kill against attacking UAS due to their size, speed, and maneuverability.

Football Field Technique

The football field technique is a simple method of estimating lead distance. The theory is that most people have played or watched football and have a concept of how long a football field is. When told to lead the UAS by one football field, everyone aims at approximately the same point in space. One person’s error in making the football field estimate will be offset by another person’s error. The variation in aiming points will ensure that massed fire is delivered into a volume of space in front of the UAS rather than on a small point. Also, the differing perspectives from which the service members view the UAS will act to further distribute the fire over a volume of space.

Aiming points used to engage threat UAS are different but may be used on a variety of different threats. An example of this technique would apply if enemy helicopters were detected, and the decision was made to engage it should be engaged as a group 5 rotary wing UAS. The rules for selecting aiming points are simple, easily learned, and retained. The various aiming points are summarized in table 5-4.

Engaging With Machine Guns

The machine gun is effective against slow-moving UAS. To sustain the volume of fire and kill a UAS, a continuous burst of 20 to 25 rounds fired using a tracer on target method, allowing the gunner to adjust rounds on target as follows:
• Vehicle’s machine guns are useful weapons against UAS. They can be fired quickly unleashing a high-volume of fire. Ensure that the area is clear of friendly personnel. Use the following guidelines when using crew served weapons.
• When UAS are hovering or inbound, aim high with the machine gun and fire a continuous burst, adjusting onto the UAS by observing the travel and impact of tracers remembering, tracers may appear to be striking the target when they are going under it.
• If engaging a moving UAS, track along its flight path using a lead of 50 meters or half a football field. Fire a continuous burst, forcing the UAS to fly through the cone of fire.

When coordinated effectively, the aircraft will fly through the unit’s cone of fire. Vehicle commanders must not try to track high-speed aircraft because they fly too fast. When enemy aircraft fly directly at vehicles, vehicle commanders are responsible for engaging them with controlled machine gun bursts of 50 to 100 rounds. Select an aiming point slightly above the nose to position the UAS in the cone of fire.

Due to the speed of some types of UAS, the best technique to use against them is to fire all automatic weapons in continuous bursts. If the UAS are inbound, aim slightly above the nose or fuselage and fire. If the UAS is crossing, use a lead of 200 meters (two football fields) and fire letting the UAS fly through the cone of fire from the machine guns. Do not try to track or traverse your fire for group 3 and above UAS since they fly too fast.

This article is an extract from "C-UAS/SUAS(1): The Counter-Unmanned Aircraft System & Drone Warfare SMARTbook (Planning & Conducting C-UAS/sUAS Operations)" by The Lightning Press. Download a free PDF sample and learn more at:  C-UAS/SUAS(1): The Counter-Unmanned Aircraft System & Drone Warfare SMARTbook (Planning & Conducting C-UAS/sUAS Operations).

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