On March 19, U.S. Marine Corps staff sergeant Louis Cardin, a field artilleryman assigned to the 26th Marine Expeditionary Unit, died during an attack...

On March 19, U.S. Marine Corps staff sergeant Louis Cardin, a field artilleryman assigned to the 26th Marine Expeditionary Unit, died during an attack on Fire Base Bell outside of Makhmur, Iraq. Coincidentally, the U.S. Army is hard at work developing a farther-firing howitzer that could help keep artillery troops out of range of enemy forces.

The Army is cooking up a suite of improvements could double the range of the existing M-777 howitzer. Right now the 155-millimeter gun, in service with the Army and Marines, can lob shells at targets up to 18 miles away.

The M-777ER version the Army is working on “will be able to reach out and hit targets … before the targets can reach them,” David Bound, the lead engineer on the project at Picatinny Arsenal in New Jersey, told Army reporters. Troops “won’t have to worry about coming into a situation where they are under fire before they can return fire.”

The modifications add fewer than 1,000 pounds of extra weight onto the older howitzers. The updates include improvements that will help gunners fire more accurately plus a mechanism to automatically load rounds into the gun.

The biggest change is the addition of new barrel that’s six feet longer. The longer M-777ER should be able to hit enemy forces more than 43 miles away. And with more powerful propellant charges and rocket-assisted shells, crews might be able to increase that range even more in the near future.

Above — the Army’s M-777ER prototype. Army photo. At top — Marines at Fire Base Bell fire shells at Islamic State. Marine Corps photo

While the changes to the M-777 might sound simple, the new gun’s extra length actually complicates its employment. Unlike older towed howitzers that hitch up to cargo trucks with their stabilizing legs, the lightweight M-777 has its tow loop right at the end of its barrel. Folded up for travel, the new version will still be more than 35 feet long.

In combat, troops could end up taking the guns off-road, up hills and over uneven terrain. With six more feet between the truck and the howitzer’s own two wheels, there’s greater potential for the barrel to flex if it isn’t sturdy enough to withstand the shock.

A bent barrel would throw off where the shells fall. A broken barrel might simply explode.

So, the project’s biggest challenge might be just convincing soldiers and Marines that the guns work. “The visual prejudice we are up against is that it looks like it may tip over with all that extra cannon,” Bound noted.

With help from engineers at Benet Labs, the Army plans to run “mobility” demonstrations to prove that the gun and its new features are ready for combat. The ground combat branch also plans to install the longer barrel on the new M-109A7 Paladin self-propelled howitzer.

Farther-firing cannons would no doubt help in the fight against Islamic State. Since the summer of 2015, the Army has lobbed hundreds of 227-millimeter rockets at militant forces from bases in Iraq and Jordan.

Launched from the back of a six-wheel truck, these GPS-guided projectiles can hit targets up to 43 miles away — the same range the Army expects of the M-777ER. The High Mobility Artillery Rocket System launcher can shoot one rocket every five seconds. But the vehicle can only fire six rockets in total before the crew needs to reload.

Marines hitch an M-777 up to a truck. Marine Corps photo

While an M-777 fires at a much slower rate of just two to five rounds every 60 seconds, a trained howitzer crew can keep that up for minutes without a break. And with their own satellite-guided rounds, the gunners can be just as accurate as the HIMARS crews can be.

“So to provide protection for … advisers in Makhmur, we realize that we need some fire support, we need some artillery to provide great protection,” Army colonel Steve Warren, the Pentagon’s main spokesman for the campaign against Islamic State, told reporters on March 21. “We scratched out a fire base there, placed the guns.”

Rocket and gun artillery have the benefit of being less vulnerable to air defenses and the weather than fighter-bombers or gunship helicopters can be. Depending on where aircraft are during an attack, these weapons might take far less time to get into action.

The trainers and Marines at Fire Base Bell are backing up the Iraqi government’s offensive to liberate Mosul. But in their current configuration, the Marine Corps’ guns can’t reach the outskirts of the terrorist-controlled city.

“The Marines fired upon the enemy infiltration routes in order to disrupt their freedom of movement and ability to attack Kurdish and Peshmerga forces,” the military stated. In short, at the moment the gunners at Fire Base Bell are mainly harassing Islamic State’s fighters. But with the M-777ER’s extra range, they should be able to hit the militants’ main defenses in Mosul’s suburbs.