Countering FPVs: Norma develops 12 gauge cartridge

In the battle against FPV drones, Sweden’s Norma, part of the Beretta holding, has developed and initiated testing of a new 12 gauge shotgun cartridge called Anti-Drone Long Effective Range (AD-LER) that is designed to provide a last line of defence against the weapons that have come to define the war in Ukraine.

The cartridge was recently used in a round of testing against ten real life FPVs (first person view drones) to explore the optimal shot to use and Paul Bradley, a ballistician, Sales and Portfolio Director at Hexagon, (a company within Beretta that provides technical assistance and sells the small arms ammunition from Norma, Swiss P and others), sat down with Calibre to talk through the development, and explain the ballistics behind countering FPVs. 

“We realised that there were not a lot of cost effective kinetic solutions to the FPV problem for troops on the ground,” he told calibre on the 2nd December. “Missiles and lasers are good, but you need to consider the economic side of warfare, and a lot of these systems are not easily portable. There are electronic means, they are partially effective and sometimes they work, but it is a cat and mouse game. You can jam and take control of FPVs, but it is common for the enemy to develop a counter to that solution quite quickly. So we arrived at a list of requirements for a kinetic solution as a kind of last line of defence,” he explained. 

The category of FPVs that Norma is looking to address with AD-LER is referred to as 5 or 7 inch (12 and 17.8 cm respectively) drones, which is in reference to the diameter of the propellers. They can be 30 cm across and are flown wearing goggles at speeds up to 112 km/h (70 mph), in Ukraine they are typically armed with an explosive munition producing fragmentation effects or a shaped charge warhead like the PG-7 to engage armoured vehicles. Increasingly they are controlled using a fibre optic cable, which reduces speed but nullifies any attempt at jamming the control signals used to pilot the drones. 

“We settled on a 12 gauge cartridge because the solution needs to be man portable, cost effective, and provide a last layer of defence that’s difficult to counter. And I think that last point is particularly important, we aren’t trying to solve this problem in its entirety, AD-LER is meant to give guys that have nothing to use against FPVs, a hope of bringing them down when everything else has failed,” Bradley said. 

“FPVs are built with ruggedness in mind.”

This video was taken during the tests and shows some of the engagements using the Benelli Drone Guardian. Credit: Norma/Hexagon. 

In tests in late November 2024, the company brought together Olympic trap shooter Aaron Heading and ten purpose-built FPVs designed to reflect the build standard of drones used in Ukraine. Three sizes of shot were tested, 4, 6, and 8 – approximately 2 mm to 3 mm in diameter from the largest to the smallest. The smaller the number, the larger and heavier each individual pellet is. A larger number means more pellets per cartridge delivering a wider shot pattern and increasing the chances of a hit, but the pellets are lighter and will lack the kinetic energy of a heavier shot. 

“Sporting cartridges used in shooting clays and pigeons can use lead pellets and number 8 shot because those targets are soft and fragile,” Bradley explained, “and they work against shop-bought drones like a DJI Mavic, but FPVs are built with ruggedness in mind, so you need to optimise for that target,” he said. 

Norma found that the size 6 shot offered the best blend of shot pattern and kinetic effect against the FPVs built for their tests. While size 8 provided the greatest chance of a successful hit, it struggled to bring down an FPV. “It’s worth noting that all three shot sizes worked on shop-bought drones at ranges up to 80 metres, it’s not particularly difficult to do,” Bradley said. The 12 gauge AD-LER cartridge firing size 6 shot was loaded with about 350 pellets made of a tungsten matrix. It was able to bring FPVs down at ranges of 30 to 60 metres, sometimes with one shot, but typically within three. 

“We tested the AD-LER cartridge against ten FPVs flying in different attack patterns and brought nine of them down,” Bradley said. They are designed to be fired from the M4 Drone Guardian, a 12 gauge shotgun from Benelli that has a forcing cone in the barrel that gives a more consistent shot pattern at long range, as well as the Beretta 1301. Both are semi-automatic shotguns with a capacity for eight cartridges, they can also be fitted with the MPS red dot sight from Steiner, which helps correct for left eye dominance, helping military shooters adjust to shooting from the right shoulder when they might be aiming primarily with the left eye. 

Threat profile: FPVs

The design philosophy of an FPV is very different from a commercial drone, which may typically be used for reconnaissance or dropping munitions in Ukraine and elsewhere. “FPVs are used for racing at high speeds, they are likely to crash at some point, and if the propellers or the frame broke every time that happened, people wouldn’t use them,” Bradley said. 

Because of this, they are built using thick carbon fibre frames and flexible and tough material for the propellers, compared with the hard plastic that dominates the construction of a DJI Mavic. Hard plastic tends to be brittle, so the lead pellets from a 12 gauge sporting cartridge might destroy the propellers on a regular drone, the software that makes it fly will then be unable to account for the change in lift and the drone will crash. “With an FPV, you’ll just put a hole in the propeller and the pilot has a chance to adjust the power going to that motor and keep the drone in the air,” Bradley said. 

“That’s not the only thing, you also need a lot of kinetic energy, more than people think. The drone is just suspended in the air, so when you hit it with a sporting cartridge a lot of the energy gets used to move the drone rather than penetrating it,” he explained. “So, you need a hard pellet like the tungsten matrix used in AD-LER, and an optimal shot pattern that will destroy a lot of an FPV’s structure.” This element of an engagement is typically referred to as terminal ballistics, it describes the performance of a munition at the end of its flight, the counter-FPV solution is also impacted by internal ballistics – the propulsion of a projectile within the firearm. “We are limited in terms of the pressure that can be behind the pellets by various things, so they can only ever go so fast. Because AD-LER uses tungsten, which is much harder than the typical shotgun barrel, we have also developed a new wad that holds the pellets like a cup as they travel down the barrel,” Bradley explained. 

An FPV can travel at speeds up to 144 km/h (90 mph) for short periods of time. They are essentially modular and can be configured to perform differently depending on what the user wants to do. But generally, they follow a design spiral. The faster the drone, the shorter its battery life and range, the slower the drone the further and longer it can fly. As payload increases, the range and speed of the drone will come down in line with battery life. The flight profile also matters, they can be very manoeuvrable, but this taxes the motors and battery life leading to shorter flight times. “The average flight time in Ukraine is between five and seven minutes, so FPV operators can be quite close to the fighting, they will also try and fly the least complex route possible to conserve battery life,” Bradley said. For the purposes of downing FPVs with a shotgun, this theoretically means that at some point the FPV pilot will have to pick a line of attack and follow it, providing opportunity to engage with a shotgun. 

Calibre comment

FPVs have spread to the Middle East and are in use by various groups in Syria and elsewhere. In Ukraine, they claimed thousands of lives and proved that when used in mass they can be effective in disabling and destroying heavily armoured vehicles. In Ukraine, the solutions have tended to lean on electronic jamming for as many drones as possible, as well as hardening vehicles with additional layers of armour designed to counter FPVs. There are emerging solutions designed to improve jamming and actively counter them from a fighting vehicle using lasers. However, for infantry on the ground, the options are typically bleak; it is difficult to hit an FPV with an assault rifle, and the only alternative after that has failed is to seek cover. This is where shotgun based solutions become valuable. The type of shooting skills developed in clay pigeon shooting would be broadly transferrable to downing FPVs. Western militaries will likely have to pursue a layered solution to small drones with a kinetic element at its core sooner or later. New cartridges like the AD-LER may offer a relatively low risk route to adding that survivability to an infantry formation.