Manning 155mm howitzers, African American gunners sacrificed themselves to defend fleeing infantry. Eleven of them were murdered by the Waffen SS, and then forgotten by the US Army.
Top Image: African American crew of an M1 155mm howitzer in action courtesy of the US Army.
An act of heroic self-sacrifice highlighted the dedicated service of the 333rd Field Artillery Battalion, a segregated African American unit that bolstered American forces in Western Europe during World War II. That sacrifice unfortunately ended in tragedy for 11 American soldiers, murdered in one of the many atrocities committed by German Waffen-SS troops, in this case with particular savagery because the victims were black. Compounding the tragedy, this atrocity was not officially recognized in the United States until many decades after the war had ended.
The 333rd was originally organized as a regiment in 1942, and trained at Camp Gruber, Oklahoma. In 1943, however, it was reorganized as the 333rd Field Artillery Group, consisting of the 333rd and 969th Field Artillery Battalions, both African American units with mostly white officers. Subsequently, two other field artillery battalions would be added to this group. The 333rd and 969th battalions were equipped with the M1 155mm howitzer, a versatile and effective truck-drawn weapon used by the US Army until the Vietnam War, and still in use in some parts of the world today.
A shipment of 155mm howitzers on their way to Europe. Courtesy Library of Congress.
Arriving in England in February 1944, the 333rd and 969th battalions shipped over to Normandy in July and provided vital artillery support to American forces through months of hard fighting, including at the siege of Brest, France.
By the time the Allies liberated Paris in August, the two battalions were known as some of the most efficient and hard-hitting artillery units in the US Army. In October 1944, the units were assigned to what was assumed to be a quiet front, in support of VIII Corps and the untested 106th Infantry Division in the Ardennes region along the Belgian-German border.
A 155mm howitzer preparing for action. Courtesy Library of Congress.
The 333rd Battalion was deployed around the small town of Schönberg in an atmosphere “tranquil to a point almost approaching garrison conditions,” as a later report would admit. Tired from months of constant service, the men took the opportunity to relax, with a recreation center that included a beer hall, bowling alley, and even a badminton court.
They were preparing a musical theater performance when the German offensive known as the Battle of the Bulge began on December 16.
The 106th Division was quickly thrown into disarray. At some outposts, black artillerymen took up rifles and fought alongside the infantry, in one case beating off a German attack and inflicting serious casualties. The German tide was overwhelming, however, driving through the defending infantry.
Recognizing the seriousness of the crisis, batteries of the 333rd and 969th battalions began pulling back under orders.
The 106th Division’s artillery commander desperately requested, however, that the battalions leave batteries behind to offer continuing support, assuring them that the main lines would be held and that they would be in no danger. He was wrong.
An M1 155mm artillery piece in action, 1945. Courtesy National Archives.
Master Sergeant Floyd Jones, an African American artilleryman serving with the 333rd Group, remembered: “We had just been sitting around awaiting orders when news came of the German breakthrough, so—get ready for action!”
Guns of the 333rd Battalion fired furiously in support of the American infantry, allowing some men to escape who might otherwise have been killed or captured. But the gunners’ heroism came at terrible cost as the Germans broke in among the howitzer positions.
The Germans captured Schönberg and, continuing to advance, shattered much of the 333rd Field Artillery Battalion, killing or capturing half of its men.
Eleven artillerymen escaped the German net and walked 10 miles away to the town of Wereth, where they were sheltered by a local civilian.
A neighbor who was sympathetic to the Germans betrayed them, however, and the Americans had the misfortune to fall into the hands of troops of the 1st SS Leibstandarte Adolf Hitler Panzer Division. Like the men of other Waffen SS divisions, these Germans were deeply indoctrinated in Nazi ideology and regarded their prisoners as racial inferiors.
American infantry near St. Vith, Belgium, 1945. Courtesy National Archives.
At 7:00 p.m. on the evening of December 17, the SS men drove their captors into the forest. There they savagely tortured their victims with rifle butts and bayonets before cutting off many of their fingers and running over them with vehicles—whether before or after the Americans were dead is impossible to say. Then they moved on, leaving the bodies behind.
The remnants of the 333rd Field Artillery Battalion fell back, joined with the still-intact 969th Field Artillery Battalion, and participated in the defense of Bastogne.
For its bravery during this action, the 969th received a Presidential Unit Citation—although the members of the 333rd who fought at Bastogne surely deserved to share in the honors.
The 11 men who died at Wereth, however, were ignored. The same US Army investigators who uncovered the atrocity at Malmedy also recovered the full details of what happened at Wereth, including the fact that—unlike the white victims at Malmedy—the black men who died there had been brutally tortured.
But the investigators made no effort to pursue the matter further, taking no testimonies even though many of the local civilians—including those who had sheltered the artillerymen—were still alive and could have provided evidence. In 1949 a subcommittee of the Senate’s Committee on Armed Services conducted a full review of Nazi atrocities during the Battle of the Bulge—and completely ignored the Wereth massacre.
Members of the family who had sheltered the “Wereth Eleven” marked the site of the massacre with a memorial in 1994, and it was expanded 10 years later.
Only in 2017, however, did Congress pass a resolution bestowing “official recognition” on the victims of the massacre: Curtis Adams of South Carolina, Mager Bradley of Mississippi, George Davis, Jr., of Alabama, Thomas Forte of Mississippi, Robert Green of Georgia, James Leatherwood of Mississippi, Nathaniel Moss of Texas, George Motten of Texas, William Pritchett of Alabama, James Stewart of West Virginia, and Due Turner of Arkansas.
During the morning of March 24, 1945, more than 9,000 men of the US 17th Airborne Division landed behind German lines on the east side of the Rhine.
While the Wehrmacht was in deep trouble, many of their units remained effective, and any available Panzers could pose a significant threat to the freshly landed paratroops. American planners had anticipated this in their preparations for Operation Varsity, and mixed in among the Bazookas and M9A1 AT rifle grenades, the 17th Airborne paratroopers had the new M18 57mm recoilless rifle.
A paratrooper with the 17th Airborne Division prepares to fire an M18 57mm recoilless rifle somewhere near Munster, Germany in April 1945. Image: NARA
The recoilless guns quickly proved their worth. At the end of Operation Varsity, the 17th Airborne’s combat report recorded that “Five tanks were destroyed, two by recoilless 57mm AT guns attached to the First Battalion, two by heavy artillery and one by a Gammon grenade.”
A Marine changes position after firing his M18 recoilless rifle during the Korean War in 1953. Image: NARA
The 17th Airborne officers also recommended that “training to include familiarization firing with all weapons to include the new recoilless type 57mm and 75mm guns”, and that “recoilless rifles should be included in the T/E of an airborne division.”
Artillery for the Infantry
“While the necessity of providing our troops with superior fire power has long been recognized, experience in this war has sharply emphasized this principle.
Warfare today is not static warfare of position, with great armies confronting each other along well-defined lines and relatively small fronts; rather it is fluid warfare, a swiftly changing panorama of breakthroughs, airborne and beachhead actions, and frequent isolated engagements.
Hence the need for highly mobile and portable weapons quickly became apparent and has resulted in such successful developments as the rifle grenade, the shoulder fired rocket launcher, mortars and similar light weapons.
As the urgency for improved accuracy and increased range in weapons of this type grew apace, the Ordnance Department initiated projects to provide equipment capable of firing high explosive shell with these characteristics, yet light enough to accompany infantry in almost every tactical operation.
Field testing of a prototype M18 57mm recoilless gun, mounted on a modified M3 tripod in Burma, December 1944. Image: NARA
A controlling factor in weapon design has always been that of weight, and weight is inevitably largely determined by the phenomenon of recoil. As recoil increases so must the weight of compensating mechanisms or support increase.
To produce equipment that would possess the desired characteristics several weapons have been designed in which recoil has been eliminated. This has been accomplished by balancing the forward and rearward momentum that occurs in firing — the simplest and most efficient method.
The elimination of recoil and consequent heavy carriages has meant that these weapons are extremely light; that they can be produced rapidly and economically and that they can be readily shipped, an important consideration when supply lines cross oceans.
U.S. troops receive training on the M18 57mm Recoilless Rifle and the M20 75mm Recoilless Rifle on Okinawa, July 1945. Image: NARA
The recoilless rifles have been produced to provide infantry with assault weapons comparable to artillery. Their light weight, simple design, and ease of handling indicate employment in a great many tactical situations heretofore unsupported by superior firepower.” — From “Recoilless Weapons”, produced by US Army Ordnance during February 1945.
Enter the Kromuskit
By World War II, the notion of recoilless guns was not completely new, but no such weapons had yet been developed for infantry use. That changed during the airborne invasion of Crete during May 1941, as German paratroopers deployed the new 7.5cm LG 40 recoilless gun (designed by Rheinmetall).
The Germans continued development of their recoilless gun concept and, by 1942, they fielded the 10.5cm Leichtgeschütz 40. Captured examples were soon in the hands of US Ordnance, and the US Army’s Artillery Section began work on a 105mm recoilless cannon using the 10.5cm LG 40 as a guide. The German style of recoilless ammunition used a plastic “blow out plug” in the cartridge case.
U.S. Marines train with the M18 57mm recoilless rifle during winter exercises in Alaska sometime in 1947. Image: NARA
At the same time, the US Army’s Infantry Section assigned a two-man engineering research team to study the recoilless gun concept.
These engineers, William J. Kroeger and C. Walton Musser, working at Frankford Arsenal, were tasked with developing a man-portable recoilless 57mm gun. This weapon was given the designation “T15” and was nicknamed the “Kromuskit”. Instead of a blowout plug, the T15 used a British recoilless development, the “Ordnance, RCL, 3.45 inch”.
The British design featured hundreds of tiny holes in the walls of the cartridge case, protected on the inside by a plastic lining. The American design team also picked up on a RCL 3.45 inch feature by engraving bands onto the 57mm projectile to connect with the T15 barrel’s rifling.
Ultimately, this gave the US 57mm weapon a higher muzzle velocity (1,200 fps) and greater accuracy than other recoilless guns of the era. The T15 was in line with most recoilless cannons, following the “1-to-9 ratio”, with 10% of the propellant gas sending the projectile downrange, while 90% of the gasses are vented out the back to counteract the forward force and achieve the recoilless effect.
Testing quickly revealed that the 57mm Kromuskit was far superior to the Artillery Section’s 105mm design, and the lighter infantry weapon was approved for production. By October 1944, the T15 received the official designation of “M18 57mm Recoilless”. Production of the guns and ammunition was slow to ramp up, and examples were not sent to troops in the field until March 1945, when 50 M18’s were sent to the ETO.
In early 1945, US Ordnance described the new M18 in the following manner:
The 57mm rifles, T15E13 and T15E9, operating on the recoilless principle, have been designed to provide an anti-personnel and anti-tank weapon of lighter weight and greater range and accuracy than other comparable light weight weapons.
This rifle operates on principles like those of a conventional gun except in the characteristics of the breech. Upon ignition of the propelling charge, a controlled amount of gas is allowed to escape to the rear, which, with the forward momentum of the shell, creates equal and opposing forces within the rifle.
The force exerted by the projectile in its forward passage through the tube counteracts the force of the gas escaping through Venturi openings in the breech. Hence, since these two forces are balanced, the rifle does not move appreciably. Moreover, the Venturi openings are designed to exert a rotational reaction which offsets the torque induced in the rifle by the movement of the projectile through the rifling.
U.S. soldiers of 7th Infantry Division prepare to fire their M18 during the Korean War. Image: NARA
The cartridge case of the round for this rifle is smaller in diameter than the interior of the chamber; it is perforated to allow radial escape of gas into the chamber and thence to the rear until controlled by the Venturi openings. The round as thus proportioned is compact and easily transported.
The rifles T15E9 and E13 differ only in the rifling of the tube. The rifling in the T15E9 is one turn in 25 calibers and in the T15E13, one in 30 calibers.
The Extendable Front Handle T3E1 and Bipod T3E1 are provided. The latter, when folded, becomes a shoulder rest, permitting the rifle to be fired from the shoulder in standing, sitting or kneeling positions.
The front handle may be extended and the bipod unfolded to furnish three-point support for prone firing. The rifle may also be mounted on the cal. .30 Machine Gun Tripod. Front Sight, T91 and Sight Mount, T120E2, provide attached iron sights, the rear sight leaf being similar to the cal. .30, M1903 rifle. The Telescope Sight T130E2 may be quickly attached to the Sight Mount T120E2.
The H.E. Shell, T22, was developed to provide a high explosive, antipersonnel round for the 57mm recoilless rifle. This round is provided with a point detonating fuse, T119E1.
The H.E.A.T. Shell, T20E2, was developed to provide a round for use against armored vehicles. It is provided with a point initiating fuse, T123E1, and has penetrated homogeneous armor plate up to 3” at 20° obliquity.
An M18 recoilless rifle team in action near Jongbu in April 1951 during the Korean War. Image: NARA
The WP Shell, T23, was developed to provide a round for smoke screening, anti-personnel effect, and for spotting. The T119E1 fuse is used with this round.
All of these rounds use a perforated steel cartridge case instead of the usual solid case. The case has a paper liner that retains the propellant charge and bursts upon ignition, allowing the release of gases through Venturi tubes in the rear of the gun. All shells have pre-engraved rotating bands to reduce the amount of pressure required to expel the shell from the rifle.
SHELL TYPES:
Smoke (WP), 57mm, T23
H.E.A.T., 57mm, T20E2
H.E., 57-mm, T22
Note: All shells weigh 2.75 pounds. All complete shells weigh 7.12 pounds.
The M18 in action during World War II
In the ETO
“We need more of these guns as soon as we can get them.” — 17th Airborne Division report after Operation Varsity
The 17th Airborne Division carried the first M18 rifles into combat during Operation Varsity, the airborne crossing of the Rhine River in March 1945. The recoilless guns were specifically detailed for anti-tank work, and special permission was initially required to fire on targets other than enemy vehicles.
Shown here is an M18 recoilless rifle mounted on M1917A1 tripod. The tripod had been designed for use with the Army’s .30-caliber machine gun. Image: Author’s Collection
An after-action report of the 507th parachute infantry of the 17th Airborne Division records:
“Anti-tank work was called for as soon as we got down. Only the turret of the enemy tank was visible. I fired one round at 600 yards and hit the turret. His firing stopped and he gave us no more trouble. It was probably a Mk. IV.”
The 57mm quickly proved itself accurate and capable, as another tank was struck in the side and set on fire while it was on the move — an almost impossible shot with a bazooka.
While the armor-piercing performance of the M18’s HEAT round was only about 3” (about an inch less than the standard M6A3 bazooka rocket), the troops were greatly impressed with its accuracy. General Miley, the commander of the 17th Airborne Division, praised the new recoilless rifles for their anti-tank capability:
“The airborne division is particularly vulnerable to armor. With the addition of the 57mm and 75mm recoilless weapons, airborne troops have the means to assist themselves against tanks and self-propelled guns. In my opinion, the recent operation has proved the practicality of the recoilless rifle, and it should be issued to units, with high priority given to airborne divisions.”
The M18 during training exercises at the Army Arctic Indoctrination School, Fort Greely, Alaska, 1949. Image: NARA
I found a few other comments about the use of the M18 in the ETO. Despite its short time in combat, the weapon clearly made a strong impression:
“The effective range of the gun for direct fire is the range of visibility. It is as accurate as an M1 rifle, and you can hit a tank any place you desire. 600 yards would be an ideal distance for fire against tanks.”
“The flashback is no tactical detriment and is no danger to the firer since the gun is so light it can easily be set up so that it has a clear area behind it.”
“Ammunition should be kept in the cardboard cartons until ready for use. It will withstand heavy handling under normal use. We have had no duds and no premature bursts.”
In the PTO
Only a handful of M18’s saw combat in the Pacific Theater, with the first significant use of the weapon coming during the latter stages of the Okinawa campaign.
The US Army publication “Weapons for Jungle Warfare”, produced in June 1944, described the anticipated use of the M18 in the Pacific.
A demonstration of the M18 recoilless rifle on Okinawa, June 1945. Image: NARA
“There is under development by the Ordnance Department a recoilless gun of 57mm caliber which may be used as a shoulder-fired weapon or be adapted to firing from a machine gun tripod.
The project for the 57mm Recoilless Gun was initiated early in 1943. The first pilot model was tested in July 1943, and the first completed service test model was demonstrated on November 9, 10 and 11, 1943.
It is believed that the maximum range of approximately 5,000 yards possessed by this arm, with its accuracy and powerful hollow charge projectile, will permit it to be utilized at ranges up to 4,000 yards for many of the functions now performed by light artillery.
The gun is breech loading and has a rifled tube. It weighs 36 pounds, fires a special 2.75 pounds projectile of the HEAT type (now under development) at a muzzle velocity of about 1,200 feet per second, and has sufficient accuracy to hit a rectangle 25″ x 33″ at a range of 600 yards.”
There were few Japanese tanks to worry about during the late stages of the war, and the M18’s HEAT round could easily penetrate any known Japanese armored vehicle. However, its portability, accuracy, and penetrating power gave GI’s an effective bunker-buster for use against Japanese pillboxes and cave defenses (this was also noted by US Army Ranger units that used the M18 during the Korean War).
10th Army Action Report: Ryukyus, March 26 to June 30, 1945
During the later phases of the campaign the 57mm and 75mm recoilless weapons were tested and used in combat against the enemy with excellent results.
A total of approximately 670 rounds of ammunition was all that was available. Based on the limited use made of these weapons, it is believed they have definite possibilities, especially for close support against fortified positions.
A gun crew of the 383rd Inf. Regt. loads a shell into the M18 57mm recoilless rifle to fire against a Japanese pillbox on Okinawa. June 10, 1945. Image: NARA
77th Infantry Division, Okinawa report
The development of the 57mm recoilless weapon and the 75mm recoilless weapon appears to be in the right direction, especially in view of many situations where steep terrain impassable to vehicles will be encountered.
Pacific Area Material Report (July 1945)
The 57mm Rifles, T15E13 and M18, operating on the recoilless principle, have been designed to provide an anti-personnel and anti-tank weapon of lighter weight and greater range and accuracy than other comparable light weight weapons. They have been found particularly effective when fired into cave entrances.
The rifles M18 and T15E13 differ only in the rifling of the tube. The rifling in the M18 is one turn in 25 calibers and the T15E13 is one turn in 30 calibers.
An extendable front handle and bipod are provided. The latter, when folded, becomes a shoulder rest, permitting the rifle to be fired from the shoulder in standing, sitting, or kneeling positions.
The front handle may be extended and the bipod unfolded to furnish three-point support for prone firing. The rifle may also be mounted on the caliber .30 machine gun tripod.
Sight, Front, M26 and Mount, Sight, M74 provide attached iron sights, the rear sight leaf being similar to that of the caliber .30 M1903 rifle. Telescope, M86C, may be quickly attached to the Mount, Sight, M74.
Post-WWII Development
In December 1948, the US Army released its “Summary of Recoilless Weapons Development”, and their findings showed that upon deeper review, the M18 was showing several deficiencies. Its weight and insufficient armor penetration were the Army weapons development board’s primary concerns.
A U.S. M18 recoilless rifle and a captured Chinese Type 36 copy compared during the Korean War, March 1951. Image: Author’s Collection
The US Army weapons development board stated in December 1948:
57mm Rifle: The present 57mm rifle is too heavy. Development and redesigning should continue to reduce the weight, improve the reliability of mechanical functioning, decrease the time of flight of the projectile, improve the accuracy, and relocate sights and operating mechanisms for the comfort of the operator.
Findings: Recoilless weapons of 75mm or smaller in caliber will not, even with the best-known designed weapon and ammunition, be able to meet the armor penetration required by the Anti-tank Defense Conference.
(Requirements set up by the Antitank Defense Conference at Fort Monroe, Virginia, for a man-portable recoilless weapon which will have an effective range of 2500 yards against the frontal armor of any potential enemy tank with 75% first round accuracy, assuming not more than 5% range determination error under optimum conditions.)
A Dutch M18 gunner with a unique over-shoulder carry. Note the “Aggressor Force” helmets for a joint NATO exercise in 1964. Image: Dutch National Archives
In summary, it is apparent that the 57mm Rifle, M18, does not meet the requirements for frontal armor penetration, or accuracy, and is not provided with sighting equipment to perform the mission.
The present weapon is classified as a close-in anti-tank weapon and due to its lack of penetration must be employed to deliver flanking fire. It is more accurate than the 2.36- or 3.5-inch rocket launchers and has a greater maximum usable range. It lacks the penetration of the 2.36-inch rocket launcher because the projectile is spin stabilized.
However, the Infantry Conference concluded: That the Infantry Regiment retain the present recoilless weapons of 57mm and 75mm caliber, and the following actions be taken.
A) Reduction of breech blast effect, flash and smoke.
B) Reduction of weight and volume of propelling charge.
C) Increase in muzzle velocity and armor penetration.
D) Improvement of waterproofing of propellant.
Korean War, and Beyond
While the M18 was standard issue for US Army rifle companies during the Korean War, its use was normally restricted to bunker-busting and anti-personnel work. Anti-tank duties had passed to the more powerful M20 75mm recoilless rifle.
A Type 36 Chinese copy of the M18 uncovered in a Viet Cong weapons cache during the Vietnam War. Image: Author’s collection
In Brigadier General S.L.A. Marshall’s 1951 “Commentary on Infantry Operations and Weapons Usage in Korea”, the M18’s use in bunker-busting is compared to the newer, but heavier M20:
“The 57 is too light for such work at ranges exceeding 1000 yards, though troops have wasted an excess of 57 ammunition trying to prove otherwise; of the weight problem with the 75, it is often left behind during movement into the higher ridges, and the attempt is made to substitute the 57 at prohibitive ranges. …
On the other hand, the 57 becomes invaluable during the closing infantry assault on an enemy-held high hill mass. Always a few bunkers remain in operation; those which were protected from the long-range fires by the folding of the ridge are likely to be almost unscathed. Falling back toward these works, after quitting the outer line of foxholes, enemy skirmishers are apt to seek protection in small caves and behind rock outcroppings. The 57 can blast them out from cover which would normally provide immunity to bullet fire.”
Dutch troops training with the M18 recoilless rifle during the early 1960s. Image: Dutch National Archives
During the late 1940s, the US government provided the M18 to several countries as part of various foreign aid packages. A set of blueprints was provided to the Nationalist Chinese, and these were captured by communist forces at the end of the Chinese Civil War. Consequently, the People’s Republic of China copied the weapon and produced it as the Type 36 (later Type 52).
The Type 36 was first encountered with Chinese troops in the Korean War, and then with NVA and Viet Cong forces during the Vietnam War. America’s 57mm recoilless soldiered on, in allied and communist hands, until the early 1970s.
It’s the most expensive single firearm sold at auction, according to Rock Island Auction Company. Pairs of guns have gone for more, but this one’s connection to the surrender of Chiricahua Apache Chief Geronimo and impeccable condition added up to a new world-record on April 30, 2016.
Captain Henry Lawton and Lt. George E. Albee served together during the Civil War. The latter went on to work for Winchester, while the former stayed in uniform and later captured Geronimo.
The friendship they forged during the War Between the States ran deep, though, so when the legendary firearm maker was rolling out a brand new carbine—the Model 1886—Serial No. 1 went to Lawton. The engraving isn’t fancy. In fact, it’s so understated it carries a timeless eloquence. The wood, too, is good, but probably wouldn’t turn too many heads.
Albee obviously knew his friend well. Lawton led troops in a rugged time, when troopers relied on their tools and personal possessions to survive and thrive in the scorching sun and pouring rain. Fancy enough to attract longing stares wasn’t—and still isn’t—an asset in the Chiricahua Mountains of the desert Southwest.
A pocket watch presented to Lawton by businessmen in New Mexico—part of the gun’s auction lot—punctuates that point. He didn’t want to attend the ceremony, but he received a direct order that he would. He described the timepiece as valuable, and from its looks it was rarely, if ever, used.
At 130 years old, the carbine is in great shape and finally, perhaps for the first time since it rolled out of the factory, back in the news. For more of the gun’s history, visit Rock Island Auction’s blog and watch a detailed video about the gun here.
Some 650 to 950 rounds per minute. That is the exact mathematical formula required to turn an enemy formation’s fighting spirit into a desperate desire to simply survive. The United States military has spent decades crafting and perfecting this formula and has ensured its fighting men and women are well versed in its many uses and applications.
U.S. Marines fire an M240B machine gun during a live-fire squad attack exercise at Twentynine Palms, California on July 27, 2026. The M240 is chambered for the 7.62x51mm NATO cartridge. Image: Sgt. Alexis French/U.S.M.C.
The official U.S. Army Technical Manual describes the M240 as “a belt-fed, air-cooled, gas-operated, fully automatic machine gun that fires from the open bolt position.” While that definition is technically accurate, it fails to capture what the weapon actually is. It is the heartbeat of American fire superiority, and the defining sound of that heartbeat over the last four decades has been the steady, rhythmic, unstoppable chugging of the M240.
Spc. Pedro Ochoa carries a M240B machine gun while rucking to his objective during the Alaska State Best Warrior Competition 2025 on Joint Base Elmendorf-Richardson. Image: Alejandro Peña/Alaska National Guard
It’s heavy, brutal to carry, and it is the undisputed heavyweight champion of medium machine guns because it does the one thing a machine gun absolutely must do without fail, no matter what: it never stops firing. Many people forget that the M240 didn’t start its legendary U.S. military career in the hands of the infantry. Long before ground troops were humping this 27-lb. behemoth up the mountains of Afghanistan or through the streets of Baghdad, it was doing dirty work inside the steel carapace of American armored vehicles.
A Marine Raider with Delta Company, 1st Marine Raider Battalion, Marine Forces Special Operations Command, fires a M240B at simulated enemy targets. Image: Lance Cpl. Jared Saul/U.S.M.C.
This is the story of how a tank’s coaxial machine gun proved so ridiculously reliable that the infantry had no choice but to steal it for themselves.
Retiring “The Pig”
To understand the M240, you first have to look at the weapons it was brought in to replace, starting with the legendary M60 machine gun. The M60 was one of the most iconic faces of the Vietnam War. It served with distinction in the hands of infantry squads and as the premier weapon for helicopter door gunners who specialized in hurling lead at the enemy while raining brass from the sky. It is an icon of American might, a Hollywood favorite, and an all-around pleasure to shoot.
Pfc. Milton L. Cook of the 25th Infantry Division fires his M60 machine gun at a tree line during Operation Cedar Falls in the Vietnam War. Image: NARA
However, even though it has its strengths, it is important to be honest about its faults and weaknesses. Troops affectionately (and sometimes aggressively) referred to it as “The Pig.” It was a maintenance-heavy weapon, requiring constant upkeep and cleaning to ensure reliability in the field.
Changing a red-hot barrel in the middle of a firefight required clumsy asbestos gloves, and as parts wore down in harsh environments, it became notorious for jamming at the worst possible moments. This was unacceptable and resulted in the loss of American lives, losses that the military hoped to prevent when searching for The Pig’s replacement.
Cpl. Randy Isaacson, a Combat Engineer, Marine Expeditionary Unit (MEU), Service Support Group 24, mans an 7.62mm M240 machine gun circa 2003. Image: SGT Zachary A. Bathon/U.S.M.C.
While the infantry was struggling with the quirks of the M60, the armored community was dealing with an entirely different nightmare: the M73 and M219 machine guns.
Sgt. Dwayne Blank, from the 2nd Battalion, 6th Marines, sights an M240 machine gun at the base camp gate, outside of Muwaafaqiyah, Iraq. Image: Sgt. Mauricio Campino/U.S.M.C.
Those weapons were used as the coaxial machine guns in early armored vehicles like the M48 and M60 Patton tanks, and their reliability was absolutely abysmal. A coax lives an incredibly unforgiving life. It is mounted inside a steel box that violently bounces across the earth at 40 miles per hour, surrounded by extreme heat, carbon and dust.
When you are buttoned up in a tank during a mechanized assault, you cannot easily reach over to clear a complicated malfunction. The military desperately needed a coax that was functionally indestructible without sacrificing lethality and reliability.
Pfc. Jonathan Ayers and Pfc. Adam Hamby emplace an M240 machine gun as part of a fighting position in the mountains of Afghanistan’s Kunar Province. Image: DVIDS
The Army looked outward for a solution and found it in the Belgian-designed FN MAG. In the late 1970’s, the military put the weapon through a grueling series of evaluations against its competitors. The results were undeniable. The new weapon’s Mean Rounds Between Stoppages (MRBS) absolutely embarrassed the competition and proved it could run filthy and hot without skipping a beat.
The Army officially adopted it in 1977 as the M240, specifically to serve as the coaxial machine gun for armored vehicles like the incoming M1 Abrams and Bradley Fighting Vehicle. For nearly two decades, this ultra-reliable powerhouse was the armored community’s best-kept secret, running flawlessly in the turrets while the infantry continued to slog it out with the M60.
Under the Hood: M240 Reliability
To understand why the M240 dominated those reliability trials, you have to look at the mechanics driving the gun. The secret behind its sustained suppression capability comes down to three critical design features: the open-bolt operating system, the adjustable gas regulator and the quick-change barrel mechanism.
Open-Bolt Operating System
The M240 fires from the open-bolt position. For the uninitiated, this means that when the gunner releases the trigger to stop firing, the bolt assembly travels backward and physically locks to the rear. The chamber is left empty and completely exposed to the open air. This is a vital safety and reliability feature for a weapon designed for high volumes of fire.
Pfc. Coty Lang carries his M240 machine gun during an early morning patrol near Combat Outpost Munoz, Paktika province, Afghanistan, in 2009. Image: Staff Sgt. Andrew Smith/DVIDS
When a machine gun sends hundreds of rounds downrange in a matter of minutes, the chamber temperature skyrockets. If a live round were left sitting inside that white-hot chamber, the ambient heat would eventually cause the gunpowder to ignite on its own. This dangerous malfunction is known as a “cook-off” and can result in serious injury to the operator or those nearby. Locking the bolt to the rear allows the weapon to vent that massive heat buildup and keeps the ammunition safe.
Adjustable Gas Regulator
The cyclic fire rate of an AK-47 is around 600 rounds per minute. The M3 Grease Gun shoots 450 rounds per minute. The fire rate of the M240 isn’t a single static number like many other weapons systems. In fact, the technical manual officially lists it as a sliding scale from 650 to 950 rounds per minute.
This variance is entirely by design, courtesy of an adjustable gas regulator located at the front of the gas cylinder. Under normal conditions with a clean weapon, the gun is fired on the first setting, churning out around 650 to 750 rounds per minute. However, as you may know, combat is notoriously dirty.
A U.S. Coast Guard Maritime Safety and Security Team member is positioned beside an M240 during maritime security operations in front of Fort McHenry. Image: Petty Officer 3rd Class Austin Canos/DVIDS
When the weapon gets choked with carbon, sand, and grime after sustained firefights, the gunner can physically adjust the gas plug to the second or third setting. This forces a higher volume of expanding gas into the system, violently driving the piston backward to punch through the filth and keep the gun cycling.
Quick-Change Barrels
Unlike the cumbersome barrel changes of the M60 era, swapping a barrel on the M240 is executed with a simple push-button release on the left side of the receiver. It should be noted that the physical reality of executing that swap depends entirely on where the gun is mounted and which variant you are operating. For the infantry variants (like the M240B or the Marine Corps M240G), the barrel features a built-in carrying handle. The gunner simply depresses the release, lifts the handle to strip the hot barrel out, and slams a fresh one in.
Marines with Headquarters Battalion, 3rd Marine Division, change the barrel of an M240B machine gun during a baseline skill evaluation on Okinawa, Japan, May 3, 2026. Image: Cpl. Adam Trump/U.S.M.C.
For an armor crewman, it is a completely different story. The M240 used as the coaxial machine gun in the Abrams strips away the heat shield and the carrying handle entirely to fit inside the tight confines of the gun mantlet. There is no handle to grab. When a loader has to swap a red-hot coax barrel in the middle of an engagement, they are grabbing raw steel using a heavy heat mitten in the cramped interior of the turret, relying on pure muscle memory to get the tank back in the fight.
Airman 1st Class Darrin Kirchner changes the barrel of an M240 machine gun during a heavy weapons training event at Fort Custer on May 21, 2021. Image: Senior Airman Kregg York/U.S. Air National Guard
Compared to the M73 and the M219 however, this was a cakewalk, as those weapons systems had archaic barrel change procedures involving the swiveling of the entire receiver, which was near impossible to do in a stressed environment.
M240 Family Tree: Tailoring the Heavyweight
Once the U.S. military realized they had an absolute masterpiece of reliability on their hands, they began tailoring the weapon to fit the specific needs of different combat units throughout the fighting force. Today, the M240 exists in several distinct configurations, but they all share the exact same rugged DNA.
The Armor Variants: M240, M240C, and M240D
As a tanker, these vehicle variants are my bread and butter. While they are fundamentally the same weapon, employing them feels entirely different based on where they sit. The standard M240 (with no letter designation) is the coaxial variant mounted directly next to the 120mm main gun in the Abrams.
Spc. Blake Briski fires a mounted M240 machine gun from an M1A2 Abrams during training at Camp Ripley in Little Falls, Minn., July 29, 2025. Image: Staff Sgt. Thomas Moeger/U.S. Army
Because of its placement in the mantlet, the loader feeds the ammo belts from the left side, over the cannon, and into the machine gun. It lacks a traditional trigger group or buttstock, firing instead via an electronic solenoid controlled by the gunner’s cadillacs. (To accommodate other platforms like the Bradley Fighting Vehicle that require a right-hand feed, the military utilizes the M240C).
Members of an M1 Abrams main battle tank crew man the tank commander’s M2 .50-caliber machine gun (left) and the ammunition loader’s M240 7.62 mm machine gun (right) in 1981. Image: NARA
The M240D is the brawler. This is the variant mounted on the skate mount at the loader’s hatch. It feeds from the standard left side and is operated manually using spade grips and a butterfly trigger. Additionally, the “Delta” model comes with an egress kit. If the tank is disabled and the crew has to abandon ship, pulling two retaining pins allows the loader to rip the gun off the mount, slap on a traditional buttstock and trigger assembly, and take it to the ground as a highly effective infantry weapon.
Marine Corps Pivot: The M240G
By the mid-1990s, the Marine Corps had finally had enough of the M60. Being naturally resourceful (read: broke), they looked at the incredibly reliable M240’s already mounted in their LAVs and tanks and realized the solution to their infantry problem was already in the armory.
Moldovan troops watch as U.S. Marines demonstrate the proper way to fire an M240G machine gun during Cooperative Osprey ’96. Image: Staff Sgt. M. A. Jones/NARA
They pulled the weapons out of the vehicles, slapped on a buttstock, bipod and iron sights, and fielded it to the infantry as the M240G (the “Golf”). It’s all about pure function and no nonsense. It lacks a heat shield, which saves weight, and retains the three-position adjustable gas plug from the vehicle variants, giving Marine machine gunners total control over their cyclic rate of fire
Army Infantry Standard: The M240B
Seeing the Marines successfully running the Golf model in the dirt, the Army finally retired the infantry’s M60’s in 1997, adopting the M240B (the “Bravo”). The Bravo is the heaviest of the ground variants, weighing in at roughly 27 lbs. The Army added a heat shield, a modernized front sight, and Picatinny rails for mounting optics and lasers.
Members of the U.S. Army’s 82nd Airborne Division march carrying 7.62x51mm M240 machine guns during the opening ceremonies for CENTRASBAT 2000. Image: Tech. Sgt. Jim Varhegyi/U.S.A.F.
Most importantly, the Bravo features a hydraulic buffer system integrated into the buttstock. This buffer absorbs a massive amount of the weapon’s recoil, making it incredibly controllable during sustained bursts. It is a grueling piece of equipment to ruck up a mountain, but the second the bipod hits the dirt, it becomes the uncontested base of fire for the Army infantry squad.
Death from Above: The M240H
The aviation community couldn’t let the ground guys have all the fun. The M240H (the “Hotel”) was developed to replace the M60D as the standard door gun on helicopters like the UH-60 Black Hawk and CH-47 Chinook. Like the tank’s Delta model, it features spade grips and a butterfly trigger, and it can be rapidly dismounted with an egress kit if a bird goes down and the crew needs to fight their way out.
A U.S. Marine fires a M240D machine gun from a UH-1Y Venom on June 15, 2026. Image: Mass Communication Specialist 1st Class Russell Rhodes Jr./U.S. Navy
The Maritime Solution: The M240N
The Navy needed a piece of this reliability for their own operations, leading to the M240N (the “November”). Designed specifically for waterborne environments, the November model lives its life on pintle mounts aboard small patrol crafts, rigid-hull inflatable boats (RHIBs), and ship decks. Because it isn’t meant to be humped through the mountains or fired from the dirt, it completely strips away the integral bipod found on the infantry variants.
A U.S. sailor fires an M240 machine gun during a live-fire exercise aboard the USS Fort Lauderdale (LPD 28) while underway in the Caribbean Sea on April 25, 2026. Image: U.S. Navy
Maritime environments present the unique hurdles of constant exposure to saltwater, sea spray, and corrosive ocean air. This can be notoriously brutal on weapon systems, but the exact same rugged mechanics that keep the gun cycling through the sand and carbon of a battlefield keep the November model chewing through belts on the open water.
The Operator’s Perspective of the M240 Machine Gun
Regardless of your job or in which capacity it’s used, operating the M240 is intensive and grueling work. If you are an infantryman humping a 27-lb. Bravo model plus heavy belts of 7.62 up the side of a mountain, your knees and back will absolutely hate you. If you are an armor crewman wrestling a jammed, red-hot coax in the pitch-black turret of an Abrams moving at 40 miles per hour, your knuckles will be busted and your hands WILL inevitably get burned (ask me how I know). The weapon demands a steep physical toll from anyone who is tasked with wielding it.
Cpl. Dominick Romero fires his M240 machine gun after receiving enemy mortar fire on Combat Outpost Terezaye, Afghanistan on Thanksgiving 2009. Image: Staff Sgt. Andrew Smith/DVIDS
However, the second you make contact and need to establish immediate fire superiority, every ounce of that weight, every scorch mark, and every drop of sweat is instantly forgiven.
As the military continues to modernize and looks toward the future with lighter, Next Generation Squad Weapons like the XM250, some might wonder if the M240’s days are numbered. The truth is, you can’t easily replace a masterpiece of reliability.
For almost 50 years, from the turrets of armored dreadnoughts to the trenches of the infantry, the M240 has done exactly what it was designed to do — never stop firing. As long as there is a need to lay down an unbreakable wall of lead to dominate the battlefield, the undisputed heavyweight champion isn’t going anywhere.
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