US Army Eyes Adding Unique 40mm Cannon To Its Stryker and Bradley Armored Vehicles

The 40mm Cased Telescoped Cannon is compact and powerful and could arm some of the service’s future Next-Generation Combat Vehicles, too.

byJoseph Trevithick|
Cannons photo


With its increasing emphasis on being prepared for a high-end ground conflict against a conventional opponent, particularly a skirmish with Russia or its proxies in Europe, the United States Army is adding 30mm cannons to some of its Stryker wheeled armored vehicles and is considering putting that same weapon on upgraded tracked Bradley Fighting Vehicles. Now, defense contractor CTA International, or CTAI, is pitching the idea of arming those vehicles, and future designs, with a larger, 40mm weapon to give them even more firepower.

On March 21, 2018, BAE Systems demonstrated CTAI’s 40mm Cased Telescoped Cannon to Army officials at Fort Benning, Georgia, which is presently home to the service’s Infantry and Armor schools. Company representatives and service members fired a total of 80 rounds and the weapon experienced no malfunctions. CTAI, which has its base of operations in France, is a 50-50 joint venture between U.K.-headquartered BAE Systems and the French Nexter Systems.

“I think there is going to be interest to let [the Army’s Armament Research, Development and Engineering Center] look at the weapon in some more detail,” Rory Chamberlain, a BAE Systems business development manager, told reporters after the live-fire event, according to Defense News. “It’s a mature cannon.”

CTAI has been working on the system since 1994 and has successfully demonstrated it in a variety of configurations. The United Kingdom and France have selected the weapon as the main armament for their upcoming Ajax and EBRC Jaguar armored vehicles, respectively.

General Dynamics UK's Ajax, which has the 40mm Cased Telescoped Cannon as its main armament., Crown Copyright.

It’s an advanced and innovative design overall, but its primary benefits are in the basic size and construction of the 40mm cased telescoped ammunition. A cased telescoped round means that the actual projectile sits inside the cartridge case with the propellant instead of protruding from the front.

As a result, the 40mm cased telescoped cartridges are roughly half the length of other 40mm rounds on the market and are even shorter than the 30mm rounds for the XM813 Bushmaster II gun the Army is testing on its up-gunned Strykers, also known as Dragoons. The beer-can shaped ammunition is wider overall, though. This makes them easier to handle and store within the generally cramped confines of an armored vehicle.

The video below offers a good visual overview of CTAI's Cased Telescoped Cannon and its ammunition.

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CTAI’s gun also uses an innovative rotating breach design that feeds in ammunition from the side and then rotates 90 degrees to align it with the barrel and form a secure pressure seal. After the weapon fires the shot, the system rotates open again and new round feeds in, pushing the empty casing out the other end.

A computerized fire control system handles the entire process. It can determine where certain types of ammunition are within the self-contained magazine, which can hold between 70 and 100 rounds depending on its configuration, and move them into firing position. This allows the gunner to load specific rounds rapidly to engage different targets.

An infographic laying out various features of the 40mm Cased Telescoped Cannon and its ammunition., BAE Systems

At present, CTAI offers six different types of ammunition to go along with the gun. These include anti-tank, anti-personnel and material, and specialized anti-aircraft rounds, along with a pair of training types.

The dedicated anti-tank round contains a high-velocity, solid metal dart to punch through more than five and half inches of rolled homogenous armor at ranges of more than 1,500 yards. This gives the weapon the ability to take out armored personnel carriers, infantry fighting vehicles, and older Cold War-era tanks, such as the Soviet T-55, which still remain in service around the world.

A slide from a 2009 CTAI presentation showing the relative anti-armor capabilities of its 40mm cannon compared with other armament options., CTAI

There are cartridges with high-explosive air-burst and point-detonating projectiles for attacking personnel, unarmored vehicles, and fortified positions. The weapon system’s ammunition selection function also allows pairing these effects together in rapid sequence.

According to Defense News, during the demonstration, BAE Systems showed how a vehicle armed with the cannon might fire a point-detonating shell into the wall of house to create a hole, before firing a pair of airburst rounds through that gap to kill enemy forces inside. Another simulated scenario involved shooting an airburst round over a main battle tank to blind its optical sensors, followed by an anti-armor round.

Cutaways of the 40mm cased telescoped point-detonating round, at left, and airburst type, at right, showing how the projecile is nestled inside the propellant in the cartridge case., CTAI

The standard mount for the gun also allows for a high-angle of fire, which allows a vehicle armed with the system to potentially engage low- and slow-flying aircraft, helicopters, and drones. It’s also a boon for fighting in dense urban areas, where other vehicles might not necessarily be able to engage targets in the upper stories of buildings from narrow streets below.

A dedicated anti-aircraft cartridge filled with 200 tungsten pellets gives the cannon a better chance of scoring a hit and the potential to more realistically engage small unmanned aircraft, a growing threat that both large nation state military forces and non-state terrorists and insurgents are employing with increasing sophistication. It seems hard to imagine that this oversized shotgun shell wouldn’t be useful against enemy personnel in the open, as well.

The uniform size means any vehicle with the cannon should be able to fire any new rounds that come along in the future. CTAI has been exploring a number of different types, including precision guided munitions, which might give the cannon a limited indirect fire capability, akin to an infantry mortar, when coupled with the high-angle capability.

And with the compact ammunition, the gun’s breech assembly can also be shorter, reducing the overall length of the gun, again an important consideration when it comes to the space constraints of an armored vehicle’s turret. The 40mm Cased Telescoped Cannon is similar in overall size to the Bushmaster II and should be able to fit in any turret that can accommodate the smaller weapon with relative ease.

A Stryker Dragoon with the XM813 30mm cannon. BAE Systems suggests CTAI's 40mm cannon should be able to fit inside this turret with relative ease., US Army

BAE hopes that this detail, combined with the gun’s various features, will make the weapon especially attractive to the Army. The service is evaluating the Strykers Dragoons with the 30mm XM813, but hasn’t yet decided whether it will adopt that combination for widespread use.

“From our point of view, Stryker lethality is open,” BAE’s Chamberlain said in a separate interview with Defense Daily. “As much as they’ve got the Dragoon … the lethality and the requirements are still to be decided.”

The Army is also looking at options for adding a new gun to the Bradley and has been leaning toward using the Bushmaster II in that case, as well. But if that upgrade requires a new, larger turret, then the 40mm Cased Telescoped Cannon could easily be another option, as well.

BAE Systems has the benefit there of being the present manufacturer of the Bradley Fighting Vehicle family. In addition, CTIA demonstrated it could fit the larger gun onto that vehicle all the way back in 1999.

A Bradley test bed armed with the 40mm Cased Telescoped Cannon in 1999., CTAI

And if the company can get the cannon onto those vehicles, it might be able to leverage that experience into a pitch to arm at least some of the Army’s still largely conceptual family of Next-Generation Combat Vehicles (NGCV) with the weapon. This program is seeking to develop an entirely new grouping of armored vehicles to replace existing Strykers, Bradleys, and M1 tanks, among others. The service is still hashing out the most basic of those requirements, but has said that it is actively looking to field manned-unmanned teams to replace existing armored formations.

The Army wants the first experimental vehicles – two manned and four unmanned – by the end of 2019 and ready for evaluations by the beginning of 2020. Modified M113 armored personnel carriers will initially fill the role of the unmanned ground vehicles, as they already have in other tests, but the two manned systems will be all-new designs.

The goal is for those experiments to inform development of a full company-size fleet of purpose-built vehicle, which would arrive by 2023. The Army wants to actually field NGCVs by 2028.

An artists conception of an NGCV that could replace the Army's M1 Abrams, showing a larger bore main gun, remote weapon stations, Trophy active protection systems, and what appears to be a self-defense directed energy weapon, among other notional features., US Army

“There is a lot of talk about the NGCV and where that goes,” Chamberlain noted after the So in an unmanned configuration on a Stryker, manned configuration on a Bradley and NGCV, who knows what that is going to be… We are looking at that.”

If the Army can keep to its aggressive development schedule, we may start seeing more robust concepts for the new vehicles soon. Depending on how impressed the service was by the demonstration at Fort Benning, some of the proposed designs might feature the larger 40mm cannon.

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