The Colt 40mm XM148: The First Service Under-Barrel Grenade Launcher

(Associated Press)

     Taken by Associated Press photographer Đặng Vạn Phước on February 26, 1968, a U.S. Marine patrols through the urban terrain that made up the city of Huế during the Battle of Huế which raged from January 31, 1968 to March 2, 1968. The battle was one of the biggest engagements of the Tết Offensive that had been launched by both the Quân đội Nhân dân Việt Nam (People's Army of Vietnam; PAVN) and the Việt Cộng on January 31, 1968. While the Battle of Huế ended in victory for U.S. and South Vietnamese forces and spelled decline of the Việt Cộng as a fighting force, the battle was the longest single combat of the war and also the costliest in terms of the lives of troops as well as civilians. In addition, the Battle of Huế and the Tết Offensive as a whole was one of the pivotal moments of the Vietnam conflict which majorly swayed public opinion against the war. In part, this was due to military officials having reported the Việt Cộng menace as being well under control. The reporting by public media on the Tết Offensive clearly showed that the Việt Cộng and their allies were still well able to attack in large numbers and inflict significant casualties which were displayed across television screens and print media.

     Returning to the Marine, he likely belonged to either 1st. Battalion, 1st. Marine Regiment or  2nd. Battalion, 5th. Marine Regiment, both of which were heavily involved in the street combat within Huế. The photograph is of interest because of what can be seen underneath the barrel of his Colt M16A1 5.56mm assault rifle: the short lived Colt XM148 40mm grenade launcher.

     Called the CGL-4 and designed by Karl R. Lewis for Colt (development having commenced in 1964), the intent was to replace the M79 40mm grenade launcher which was similar to a squat shotgun as it used a break-open breech for loading the grenade. But for the grenadier, it meant not only did he have to carry his M16 rifle (some grenadiers only carried a pistol sidearm instead of a heavier rifle), but he also had to carry the M79 which added to his burden in the field. The XM148 was designed to integrate the grenade launcher with the rifle and thus eliminate the need for the grenadier to carry two separate weapons. The CGL-4 was accepted by the U.S. Army following a competition and in July 1966, Colt received an order for a little over 20,000 XM148 grenade launchers with the first deliveries to be completed and received in South Vietnam for issue by December 1966. By the summer of 1967, the order had been delivered in full.

     The XM148 was connected to the M16A1 by way of a special handguard that replaced the standard M16 handguard of the rifle. To load, the grenadier pushed the barrel forward by depressing a button on the back of the grip (seen here held by the Marine's left hand) and tilting the grip forward to release it from the catch. Once the single 40mm round was loaded, the grenadier then pulled the barrel back to the closed position using the grip until it locked on the catch. The launcher was cocked by pulling back on a lever (hidden in shadow in the photograph) on the rear of the breech. The trigger for the XM148 was interesting in that it extended past the magazine well. This allowed the grenadier to fire the launcher without taking his hand off the rifle's pistol grip. The trigger can be easily seen in the picture. Not visible is the launcher's sight which was fitted to the left side of the weapon. This was an adjustable, articulated sight with a front post that had a maximum graduation of 400 yards. Also on the left side of the XM148 was a safety lever. All told, the XM148 had a weight of 3.1 pounds (compared to 6.5 pounds of the M79) and was 1.4 feet long. With a muzzle velocity of 244 feet per second, the effective range of the XM148 was 400 yards.

     Unfortunately for the U.S. military, the XM148 did not perform well in the South Vietnam theater of operations. The launcher was relatively complex and had numerous small components that had a bad habit of getting lost when soldiers serviced the weapon in the field. Another major problem was the extended trigger. As it was exposed, the launcher's trigger was subject to accidental discharges either by the soldier himself or the weapon getting caught on foliage or the soldier's own equipment. Despite the trigger having between a 6 to 11 pound trigger pull, in the heat of battle, this could easily be overcome. Another complaint by troops was the 30 pound trigger pull of the cocking lever as well as the sight that protruded from the left side was also prone to getting caught on equipment and branches. 

     By May of 1967, the XM148 was declared by the U.S. Army to be unsuitable for field use but some lingered on in front-line service (mainly with special forces) until it was replaced by the 40mm M203 under-barrel grenade launcher in 1969. Besides U.S. Marines using the XM148 in limited numbers, the U.S. Air Force Security Forces also utilized it as well as the Australian Special Air Service Regiment. Amazingly, the U.S. Air Force continued to use the XM148 for training purposes through the 1980s with the last XM148 launchers finally disappearing from military use in the early 1990s.

Primary Source:

Owen, J.I.H. Brassey's Infantry Weapons of the World (New York: Bonanza Books, 1979)

 

Battle of Kwajalein: Armor Disparity

(U.S. Marine Corps)

     From January 31, 1944 to February 3, 1944, the Battle of Kwajalein took place on Kwajalein Atoll in the Marshall Islands. It was to be a hard lesson learned for the Japanese and a morale boosting victory for the U.S. The U.S. committed the V Amphibious Corps which was comprised of the 4th. Marine Division, the U.S. Army's 7th. Infantry Division, 22nd. Marine Regiment, the U.S. Army's 106th. And 111th. Infantry Regiments, and Underwater Demolition Teams 1 and 2. Arrayed against this formidable force was the Japanese 1st. Amphibious Brigade, 2nd. Mobile Battalion, and the 22nd. Air Flotilla. The attack, called Operation Flintlock, was a multi-stage, two-prong assault along the numerous small islands which made up Kwajalein Atoll. The two main thrusts were against Kwajalein and Roi-Namur. Tasked with taking Roi-Namur was the 4th. Marine Division. First, the division took the tiny islands of Ivan, Jacob, Albert, Allen, and Abraham all within the initial start of the operation. The unit landed on Roi-Namur on February 1, capturing half the island by the end of the day then taking the remainder on February 2. The division lost 206 men, suffered 617 wounded, and 181 men missing in action. The Japanese defenders fought to the last with 3,500 men killed with a mere 87 soldiers being captured. The Japanese found that defending on the beaches without defense in-depth was a recipe for failure. For the U.S., it proved their revised tactics worked and it was the first victory within the Japanese territorial sphere.

     The photograph depicts U.S. Marine Private First Class N.E. Carling posing beside the M4A2 medium tank “Killer”. The tank belonged to Company C, 4th. Tank Battalion, 4th. Marine Division and the photograph was taken following the Marine victory on Roi-Namur. This photograph is one of several of “Killer” which are commonly seen in publications because of its war trophy mounted on the engine deck. The trophy is a Japanese Type 94 tankette and these photographs are often used to illustrate the disparity between U.S. tanks and those of the Japanese. To be fair, the Type 94 was never intended to battle other tanks and so the comparison isn't a very good one. Development of the Type 94 started in 1932 as a tracked vehicle which could supplement or replace wheeled armored cars as the latter had limitations, especially when it came to what terrain it could operate in. The prototype was completed in 1934 and after field testing, was put into production beginning in 1935. By 1937, some 823 had been built. The Type 94 was designed for reconnaissance, supply transport (it used a special tracked trailer for hauling), and if need be, infantry support. Armor protection for the two man crew was a maximum of 12mm down to a minimum of 8mm. The armament consisted of a single, turret-mounted Type 91 6.5mm machine-gun which was later upgraded to a Type 92 7.7mm machine-gun. The Type 94 was 5.4 feet high as well as wide and was 10.1 feet long with a total weight of 3.4 tons. Although the Type 94 was superseded by the Type 97 Te-Ke tankette in 1936, the Type 94 remained in service in some Japanese units until the end of the war. Which unit this particular Type 94 belonged to is difficult to say as both the 1st. Amphibious Brigade and the 2nd. Mobile Battalion were equipped with the type and there is no unit identification visible in the picture.

     The sides of “Killer” are protected by wood boards and these modifications were made in the field to defend against Japanese magnetic mines, namely the Type 99 mine. The mine contained 1.5 pounds of TNT or RDX explosive. A feature of the Type 99 was that two of them could be stacked together to increase the armor penetration. A single Type 99 could pierce 19mm of armor but together, two of the mines could penetrate 32mm of armor which was very close to defeating the 38mm of side armor the M4A2 had.

     Finally, of interest, PFC Carling is resting his hand on the fender of a Type 97 Te-Ke tankette and the crew of “Killer” have stuffed a duffel bag into the driver's compartment of the Type 94. In addition, the box-like structure on the rear of “Killer” is the exhaust adapter for the tank's deep-wading equipment. A exhaust stack would have been fitted to it while another similar stack would have been secured as an air-intake for the engine. This equipment allowed the M4 to come ashore in shallow water (though it could not fully submerge).

Observation Squadron VO-9M: Deployment to Haiti

The men of VO-9M in Gonaïves, Haiti. Photograph by 1Lt. Louie Bertol.

     On July 28, 1915, the United States landed 330 U.S. Marines in Port-au-Prince, Haiti. Their mission was to protect "American and foreign" interests in the country. Haiti, by this time, was already unstable politically and various militia (nicknamed cacos) roamed the land and carried out numerous coups. The U.S. was also concerned about Imperial German influence in the region, including the monetarily powerful German minority within Cap-Haïten and Port-au-Prince. This would see the U.S. seize Haiti's gold reserve in 1914 and in February 1915, the dictatorship of Vilbrun Guillaume Sam came into power until several cacos overthrew and brutally killed him. This was the final straw which caused the U.S. to act, namely to defend her economic interests. The occupation, which lasted until August 1, 1934, was one of combat with the various militias who rebelled against the occupation, the assumption of much of the Haitian government's power in regards to running the country to the exclusion of Haitian political leaders, and efforts to improve the country's infrastructure. It was little over 19 years of turmoil, upheaval, and resentment. 

     Throughout the occupation, the U.S. Marines kept aviation assets in-country and U.S. Marine Observation Squadron VO-9M was one. This 1931 unit photograph depicts the men of VO-9M while in Gonaïves, Haiti. It was taken by First Lieutenant Louie N. Bertol. The flying boat behind the men is not actually a Marine aircraft. It was a Consolidated Commodore that was flown by Pan American Airways of which Gonaïves was a destination the airline serviced. The Marines, however, availed themselves of Pan American and used the carrier to ferry important personnel to and from the mainland as well as carry correspondence back to the United States. VO-9M was equipped with Vought SU-2 and SU-3 Corsairs (scout designation of the O2U) and missions included reconnaissance, mail delivery, passenger transport, and medical evacuations. By June 29, 1934, VO-9M commenced preparations to return to the mainland, specifically, to Marine Corps Base Quantico in Virginia. Squadron property was assessed on what would remain behind, be destroyed, or returned with the squadron. Much of the physical infrastructure was to be turned over to the Haitians but the U.S. Navy felt that the unit's hangers and shops needed to be dismantled and sent to Marine Corps Recruit Depot Parris Island in South Carolina. On August 15, 1934, the aircraft of VO-9M departed Haiti for good. 

     Sometime late in 1934, VO-9M would be redesignated as Scouting Squadron VMS-3 ( the "Devilbirds") and they operated from St. Thomas, Virgin Islands until inactivated on May 20, 1944. VMS-3 flew Grumman J2F Ducks, Vought OS2N Kingfishers, and finally the Douglas SBD Dauntless.

     The aircraft in the background are difficult to make out but appear to be Curtiss F6C-4 Hawk fighters.

The 37mm M1916: Soldiering On In WW2

     The Canon d'Infanterie de 37 Modèle 1916 TRP (standing for Tir Rapide, Puteaux; fast firing [made by] Puteaux), whose name was shortened to 37mm mle.1916, was a weapon whose purpose was to bring under direct fire hardened emplacements, such as machine gun “nests” and other hard points so as to facilitate assaults against enemy lines. As it was to be hauled into action by the crew, the mle.1916 was small and four men could carry the gun once broken down. In action, only two men were needed to operate it. A well trained crew could fire up to 35 rounds per minute. Entering service in 1916 with the French army, the gun was accepted into service with the U.S. military as the 37mm M1916. 

     The M1916 was not well liked and it was felt that mortars were better able (and in a way, more safely able) to bring enemy strongpoints under fire. Nevertheless, the M1916 remained in U.S. service for many years after the end of World War One, typically in a training role. This photograph depicts U.S. Marine soldiers “training” with the M1916. Given the Marine in the background is relaxing and reading a newspaper, this photograph was most likely staged rather than showing actual range training. 

     By 1941, the M1916 was either in storage or repurposed but during the Philippines Campaign (1941-1942), the M1916 was brought out in order to plug shortfalls in equipment. France still had the mle.1916 in service by 1940, using it to fill out anti-tank units still waiting for the more potent Canon de 25mm Semi-Automatique Modèle 1934 anti-tank gun. Enough mle.1916 guns remained that the Germans put captured examples into service as the 3.7 cm IG 152(f). The Japanese thought enough of the gun to obtain a license from the French to build it as the Type 11, putting it into service in 1922. The Type 11, despite being obsolete, would remain in service with the Japanese until the close of the war in 1945.