Why the Army is looking abroad to close a widening artillery gun gap

More than two years into observing an artillery war play out in Ukraine, the U.S. Army finds its own gun technology options lacking.

The service’s current arsenal is either old, as is the case of the towed M777, or lacking the desired range for future conflicts against near-peer armies, exemplified by the latest version of the Paladin self-propelled howitzer, made by BAE Systems.

The recent cancellation of an effort to mount an unwieldly long barrel on a Paladin body — length determines range, generally speaking — has forced the service to start from square one yet again.

The Army quietly halted the yearslong prototyping effort, dubbed the Extended Range Cannon Artillery, or ERCA, a year ago, announcing only this March that “engineering challenges” had turned out to be insurmountable, as acquisition chief Doug Bush put it.

In short, the program struggled with technology associated with the 30-foot-long gun tube the Army wanted in order to achieve a 70-kilometer range. Even manufacturing 58-caliber guns at Watervliet Arsenal, New York, the country’s one-stop shop for cannon tubes, would have required extensive investment to build at a desired rate.

Now the service is looking for fresh options available abroad, with urgency dialed up by the results of a tactical fires study completed this year that said the Army risks falling behind.

“We’re leaving our aperture wide, because our studies have shown that by 2035 against a near-peer adversary in large scale combat operations, we absolutely need an ERCA-like capability — and where we pursue that now is pretty important,” Brig. Gen. Rory Crooks, who is in charge of long-range precision fires modernization within Army Futures Command, told Defense News in an interview ahead of the Association of the U.S. Army’s annual conference.

“We want to make sure that we can lean toward introducing this capability to our forces by the 2030s,” he added. “So, what that’s driven us to do is to look for mature and available platforms out there, both domestically produced and foreign. … We’re going to determine what is mature, what is available.”

Global roadshow

While making up for time lost with the long-barreled Paladin, the service gets a chance to evaluate prospective gun candidates in their countries of origin.

“Things are a bit delayed,” Army acquisition chief Doug Bush told Defense News, “but that’s because we’re kind of doing a global roadshow rather than making everybody come to Yuma, which is the feedback we received, which is reasonable.”

The Army had held a demonstration of available mobile howitzers at Yuma Proving Ground, Arizona, in 2021, but the service put the pursuit to find a ready-to-go system on the backburner in favor of investment in ERCA.

The team traveling to demonstrations and gathering information is “up and running,” and all demonstrations are now scheduled, he said in an interview prior to the AUSA conference.

“We had many companies interested, which is good, and what we’re really asking to see is what they have that’s producible today, already in production or ideally already fielded, so that we could adapt quickly for U.S. Army use,” Bush said. “When combined with new munitions, [that] gets the ranges that were envisioned in the original ERCA requirement.

“I hope we can do this faster for the Army than starting all over with a whole new development program. I would much rather spend dollars procuring things to appeal to soldiers than doing [research and development] for that last 1% specialness we seek. That’s a constant frustration, to be honest.”

The companies chosen for demonstrations are American Rheinmetall Vehicles, Elbit Systems America, General Dynamics European Land Systems, BAE Systems and South Korea’s Hanwha.

Demonstrations will begin this month and run through December, Maj. Gen. Glenn Dean, the Army’s program executive officer for ground combat systems, told Defense News.

The companies will show specific capabilities that the Fires Center of Excellence has defined as key driving capabilities needed for future fights.

“What do you need for long-range division fires? What do you do to replace towed artillery?” Dean posed. “Ultimately, we also need some cannon modernization in our existing self-propelled howitzer fleet. There are systems on the market that could do any two or three such requirements, and what we’re trying to do through the demonstration is help the Fires Center choose.”

While Elbit demonstrated its Atmos self-propelled howitzer system in 2021, the company has chosen to put its Sigma howitzer in front of Army officials this time around.

Sigma is in full-rate production in Charleston, South Carolina, and is fielding the cannon system to the Israeli Defense Forces, according to Luke Savoie, the company’s president and CEO.

Sigma’s base is an Oshkosh Defense 10×10 platform, designed to be “highly mobile,” with fast road speeds and the ability to go off-road, Savoie said. The system is able to shoot any direction while moving, he added.

“I don’t want to be forced to face my vehicle toward the enemy … so 360-degree shooting has been something that we’ve done a lot of investment in,” Savoie added.

Sigma is fully automated, with the three-person crew never needing to leave the cab of the vehicle to fire from the howitzer’s deep magazine, according to Savoie.

Rheinmetall, meanwhile, will demonstrate the RCH 155, a howitzer developed through a joint arrangement between the company and KNDS and created from an association of Krauss-Maffei Wegmann and Nexter, according to company officials. The system is integrated onto a Boxer armored fighting vehicle.

Archer, a BAE Systems mobile howitzer, will make a return in the upcoming demonstration. The company brought Archer to Yuma Proving Ground, Arizona, in 2021 and has taken feedback from the effort and made a variety of improvements, according to company vice president Jim Miller.

Archer’s base platform is a 6×6 articulated Volvo truck and will be featured at BAE’s booth on the AUSA 2024 expo floor. It will be test-fired for the U.S. Army in Sweden, where it is fielded to the Swedish Army.

“It’s the same one that’s in Ukraine,” Miller noted, referring to European donations of the weapon to Kyiv’s forces.

While Archer is on a Volvo platform, it has also been integrated onto a German 10×10 MAN truck for an ongoing competition in Switzerland. Meanwhile, BAE is in a design effort with Oshkosh to put it on one of their 8×8 trucks, Miller said.

“It’s a very modular system,” he noted.

Archer engineers have been collecting a great deal of data out of Ukraine, Miller added. The system can be moving down a road, receive a mission and, within 30 seconds, stop and begin shooting — with an autoloader — fast enough to get four or five rounds off within 20 to 30 seconds. It’s then able to hit the road again in another 30 seconds, Miller said.

Hanwha USA officials told Defense News the company would demonstrate its K9A1 system. It is showcasing the A2 version at AUSA’s annual conference for the first time. The K9A2 has a fully automatic handling system and turret and an increased fire rate of 10 rounds per minute, officials said.

These capabilities are an upgrade from the six to eight rounds per minute capability of its legacy A1 variant. The K9A2 is slated to be the only tracked vehicle that will be demonstrated this fall.

General Dynamics Land Systems plans to demonstrate its Piranha system on a 10×10 platform using the same gun mounted on the KNDS-Rheinmetall RCH 155.

The Army plans to wrap up demonstrations and move into a competitive evaluation through all of fiscal year 2026, eventually coalescing around the core features of an envisioned capability it calls “mobile tactical cannon,” Crooks said.

“By the end of FY26 we anticipate downselecting, and by FY27 we anticipate having a contract awarded for a certain number of cannons,” Crooks added.

But it’s not necessarily a simple acquisition pathway. One challenge lies within mechanical engineering to ensure charges are compatible.

“We’re seeing in Ukraine — and we have done the work to understand — what [munitions] you can shoot out of what [artillery],” Bush noted, referring to a multitude of round variations tied to specific gun barrels.

Another challenge is related to software and ensuring designs can be compatible with the Army’s artillery fire control and communications systems, Bush said.

“If we go with a system we don’t currently operate, one option would be to buy some limited number of whatever is extant on that platform with a path to then adapt it over time to Americanize some of the electronics,” he added. “But I think the urgency of the need will drive that decision.”

The Army’s artillery solution doesn’t just rest with a mobile tactical cannon, Crooks emphasized.

“Our studies have shown that we have to have a new mission cycle time,” he said.

The operational environment — in Ukraine, for example — is showing the service that “we’re always under some kind of persistent surveillance,” Crooks said.

“Whereas in the past, a cannon crew could roll into position, get in place — at their leisure almost — and then it [wouldn’t be] until that first round cleared the muzzle break that they would anticipate counter-battery effects,” he said. “Now, once we stop, that’s when the clock starts.”

Meanwhile, the Army hasn’t given up hope that the M109 Paladin can be further enhanced, even though its 39-caliber gun tube is incompatible with most of the munitions being used by the rest of the world, according to Crooks.

“That platform is upgradable, potentially to a 52-caliber cannon that could shoot farther,” said Bush, adding that the large inventory of the weapons resident in the Army makes for a good reason to continue investing.

Finally, BAE in November will run the M109, with a Rheinmetall 52-caliber gun tube, through a live-fire qualification event in Minnesota, according to Miller.

Projecting projectiles

One of the Army’s more successful efforts to get better range out of cannon artillery is developing new rounds that, when fired from any caliber cannon, still achieve greater distances with better accuracy.

The Army’s XM1155 is an artillery projectile with the ability to fire within desired cannon ranges, Crooks said. And there is other work ongoing on the propellant.

Combined, those two efforts “might allow us to achieve ranges that are really, truly relevant to a division-deep area,” he noted.

The XM1155 program includes Boeing and Nammo’s ramjet capability and BAE’s Scorpio guided projectile round.

BAE’s recently rebranded “Scorpio” projectile has been fired from 39-caliber tubes and M777 howitzers and has achieved over 100-kilometer ranges in tests, Miller said.

A year ago, the Boeing-Nammo team set a new record for the longest indirect fire test of the ramjet-powered 155mm projectile with the ERCA prototype.

The Army still needs a new propellant, however, considering its current version is highly corrosive, contributing to gun barrel degradation and erosion.

Rheinmetall officials have said the company is focused on helping the service change the material used in 39-caliber barrels, because the same material won’t cut it in a 52-caliber tube.

Company officials said they are hoping to bring the solventless-based propellant technology to Virginia’s Radford Army Ammunition Plant for tests.

The service is also considering layering rocket capability at the brigade level, Crooks said, because adversaries are expected to have rockets at that echelon as well.

The Army is developing a capability of reducing the diameter of rockets, so a Multiple Launch Rocket System, or MLRS, pod can carry up to 30, a dramatic increase from the six-per-pod solutions like the Guided MLRS.

The service will also have to decide what to do about towed artillery systems, a capability some officials in the service believe is now dead.

The emplacement and displacement stop times associated with towed howitzers take much too long in operational environments like Ukraine. While Ukrainian forces have found ways to continue to use them, they require extra camouflage elaborate cover and concealment.

“They’re really versatile, and they’re great for light forces in that respect,” Crooks said, but “we know we have to do something to get faster [with] emplacement, firing and displacement, and there’s probably some physical limits we’re going to hit with towed artillery.”

The Army plans to finish a second iteration of its previous tactical fires analysis by the end of the year, which could lead to further trade studies and possible future investment, Crooks said.

The question is whether the Army will have the money.

“We’re leaning forward, as we do future budgets, to try to make sure we have that option to go fast if the choice is made to go fast with an existing system,” Bush said, “because it means more than just the system. It also means ammunition and charges. … So, that’ll be a big decision.”