An Army captain’s research paper, written at a Marine Corps professional school, criticized the service’s move to a new rifle and reignited a long-standing debate among infantrymen: heavier caliber or more rounds?
In 2018, the Army began developing its Next Generation Squad Weapon rifle, the XM7, as a replacement for the M4A1 carbine. Compared to its predecessor, the Sig Sauer-produced XM7 fires a heavier round that the Army says improves “accuracy, range, signature management, and lethality.”
But the larger 6.8mm round comes with a price: the XM7 can only carry 20 rounds in a magazine, while the M4’s standard load is 30.
Army Capt. Braden Trent argued in a recent academic paper that the lower ammo count was a major flaw. Combat training and marksmanship experts who spoke with Task & Purpose were split.
Brig. Gen. Phil Kinniery, commandant for the Army’s Infantry School and Maneuver Center of Excellence at Fort Benning, Georgia, was adamant that the new XM7 is an improvement on the firearms used by the Army for 20 years of war in the Middle East.
“From having been in several firefights throughout my career and deployments in Afghanistan and in Iraq, that [6.8mm round] round stops the enemy,” Kinniery told Task & Purpose. “What we’re actually bringing to infantry soldiers or, really, the close combat force across the Army, is something that stops the enemy at one round versus having to shoot multiple rounds at the enemy to get them to stop.”
Trent wrote his report as part of a fellowship program at the Marine Corps’ Expeditionary Warfare School. He presented his findings at a Modern Day Marine exhibition in Washington, D.C. April 29, criticizing the Army’s new rifle, specifically its capacity for fewer rounds.
Though he developed the paper as a student at the Marine school, his work was not sponsored or endorsed by the Army, Marine Corps, or Defense Department, according to his paper.
Trent observed a platoon’s live-fire exercise at Fort Campbell, Kentucky, where elements of the 101st Airborne Division have been testing and carrying the rifle for over a year. Trent watched soldiers run “almost completely out of ammunition” in 10 minutes while using XM7s to suppress a simulated enemy as fellow platoonmates made tactical maneuvers. By 15 minutes into the exercise, their situation was even more dire, as soldiers had to retrieve spare magazines from radio operators, medics and platoon leaders.
The issues raised by Trent represent longstanding disagreements within the infantry on the weapons that soldiers carry, dating as far back as the 1960s, said Thomas McNaugher, who wrote a book on the Army’s transition from the M14 to the M16 rifle.
“The rifle may look like a simple technology, but it is the last ditch defense weapon of the average infantry soldier, so it’s a personal thing and there are about 1,000 opinions out there about the best size round, the best range,” McNaugher said. “Changing rifles is often very controversial.”
Mark Cancian, a retired Marine colonel and current senior advisor on defense for the Center for Strategic and International Studies, a Washington D.C. think tank, said there are two camps of thought: those who prefer to do more with less and using a heavier round, versus others who want a higher volume of fire, lighter recoil and less weight.
“You’re never going to sort of bridge that gap because it’s baked into the military problem,” Cancian said. “People who are expert marksmen value the heavier caliber, and people who aren’t, don’t. The former tend to be more heavily represented in the infantry, of course, but they’re particularly represented in rifle teams and snipers and these elite shooters.”
An Army marksmanship instructor told Task & Purpose that the service will have to rethink how it teaches soldiers to shoot with the new rifle.
“We need to account for every one of our rounds that we shoot — marksmanship matters,” the instructor said, speaking on the condition of anonymity because they weren’t clear to speak to media.
Suppression
Close combat forces are expected to carry out firefights with the enemy, and with that come tactics like suppression, or firing to prevent the enemy from being able to fire back or to protect a friendly squad during maneuvers, according to the Army’s ATP 3-21.8 manual for infantry rifle platoons and squads.
In his paper, Trent argued that infantry soldiers’ suppression tactics could be impacted by needing to reload more often. The consequences of having fewer rounds could be critical in a future fight where the military is preparing for limited logistics and resupply.
“It is unlikely that an infantry company will be provided with constant logistical support,” he wrote. While the XM7 could be useful for suppressing targets in a single engagement, “it is not likely” that those soldiers would get a timely resupply for a subsequent mission.
Army officials said they’ve run tests in which the rifle is used to both attack an evenly matched opponent and defend against a larger one. An operational assessment of the NGSW “specifically addressed this concern with a threat ratio of one-to-one in the offensive scenario and three-to-one in the defensive scenario,” according to David Patterson, a spokesperson with Program Executive Office Soldier, which is in charge of the rifle development. “The resulting [assessment] allowed both a live fire squad attack and counterattack to be conducted with ammunition remaining.”
McNaugher investigated the trade-offs when the Army went from the M14’s more powerful and accurate 7.62mm round to the M16’s smaller and lighter 5.56mm round. The M16, he wrote in a 1979 RAND essay, allowed for more “spray-like automatic fire” that “was the product of newer trends in rifle design based on the premise that marksmanship had at best a limited role to play on the battlefield.”
From McNaugher’s own experience in Vietnam, he said the simple idea of having more or fewer rounds before having to reload was at the forefront of his mind as he trudged through the jungles and worried about being ambushed. He said the issue is “an existential question for the infantrymen.”
“I was forced to carry the 45-caliber pistol, which was about nine rounds and there had been Browning 9 millimeter pistols at 13 rounds, and I really wished I could have carried that,” he said. “In the end, it didn’t matter. I never got ambushed, but that question of how many rounds you can fire before you have to reload is an important one.”
Retired Marine Col. J.D. Williams, an adjunct defense policy researcher with the RAND Corporation, told Task & Purpose in an email that various exercises could lead to “different conclusions about magazine capacity.”
Williams said marksmanship proponents argue that higher magazine capacity “encourages indiscriminate fire and expends ammunition supplies more rapidly.” Smaller magazines lead to more frequent reloads, which “can create a lull in fire that the enemy can exploit,” he said.
“It is not surprising that firepower exercises could reach different conclusions about magazine capacity, as the structure of the exercise will impact outcome of the exercise,” Williams added.
Kiniery said if suppression is defined as being able to identify a target, use a “lethal round,” and suppress their movement, then the new rifle does just that.
“The power of this weapon system and the round that we’re giving the soldier far exceeds the capability of the 5.56, so no longer can you hide behind a tree,” Kiniery said. “No longer can you hide behind a wall. When we know you’re there, we’re going to be able to kill you.”
Lower capacity, more mags to carry
The XM7 has a 20-round capacity compared to the Army’s previous M4A1 30-round magazine. Soldiers’ current basic combat load means they carry seven magazines into battle for M4A1 carbines, which equates to 210 rounds. Soldiers with the XM7 would have 140 rounds.
“A 70-round difference may not seem significant, but to the soldier in the fight, it absolutely is a difference,” Trent said at Modern Day Marine.
To compensate for lower magazine capacity, soldiers could carry more magazines, but that would add weight.
An unloaded XM7 weighs 8.18 pounds, while the unloaded M4A1 weighs 6.54 pounds. Add the suppressor to the XM7, and that goes up to 9.84 pounds, a difference of more than three pounds from the older rifle, before loading it with heavier ammunition, according to Trent’s paper.
The marksmanship instructor told Task & Purpose that soldiers needing to carry a heavier rifle, an optic, a suppressor, and extra ammunition is a concern for large-scale combat operations. As the Army trains soldiers on new concepts for 21st-century combat, where detection by drones and sensing technologies reveal troop locations, soldiers will be expected to physically move locations more often and across greater distances.
“Walking up and down the mountains out of Afghanistan, if I had to carry a full combat load of this and it weighs X amount more, that would suck,” the marksmanship instructor said. “I’m literally just carrying too much weight.”
The issue of how much soldiers carry into battle is something that the Army has long known about and is actively working to improve by getting rid of excess batteries and cables that have accumulated over the years.
Kinniery challenged the universal basic load amounts, saying that each formation will carry more or less ammunition, depending on what their commanding officer decides is needed. He also said that the common practice of carrying seven-round magazines could be adjusted.
“One of the first questions I asked when I took the job over is, where did the science come from for having 210 rounds, and where did that get justified?” Kinniery said. “I have searched for the science on this, and I’m still looking for it.”
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