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Browning’s Fabulous Fifty

By Rod Woods

Known to generations of US GI’s as “Ma Deuce”, the .50” Browning M2 machine gun is usually colloquially known in the rest of the Western World as “The Fifty”. Through WW2, Korea, Vietnam, Iraq, Afghanistan and countless other minor actions, the thumping beat of the .50 Browning has inspired thousands of Allied servicemen, and sent fear through those on the receiving end.


The inspiration for the development of both the cartridge and the gun began in WW1 when it was recognised that something more powerful than the normal rifle calibre machine guns was needed against fortified positions, aircraft that very quickly out-ranged existing weapons, and to combat the newly developed tank.


The Germans were the first off the mark with their 13mm TuF (Tank und Flieger) which was developed for use with an oversize version of the Maxim gun. Although some of these heavy machine guns were manufactured, there is no record of their use in combat.


The 13mm TuF cartridge did see considerable service during 1918 in the massive bolt-action Mauser T-Gewehr, the World’s first anti-tank rifle, several examples of which were bought back to New Zealand as souvenirs. The 13mm TuF was a bottle-necked rimmed cartridge which fired a 795 grain pointed armour-piercing projectile at 2,650 fps and was capable of pentrating 25mm of steel at 250 metres.


An M2 HB model with a folded M3 tripod, traverse and elevating mechanism, cleaning set, headspace & timing gauges, “butterfly” wrench, spare barrel and bag.


The commander of the American Expeditionary Force in Europe, General “Black Jack” Pershing cabled the US in April 1918 requesting the development of a large-calibre machine gun round. The requirement was for a projectile of at least 670 grains with a minimum velocity of 2,700 fps.


Winchester began developing the cartridge while John Browning began work on the gun at the Colt plant in Hartford. The original request was for a rimmed cartridge but this was soon changed to a rimless design. The new gun was basically an enlarged version of Browning’s successful .30 calibre M1917 machine gun, and was ready for test firing on 15 August 1918.


It was found that the Winchester cartridge did not meet the required performance level and development was shifted to the US Government’s Frankford Arsenal along with a large quantity of captured 13mm TuF ammunition for examination and comparison tests.


“...the New Zealand Armoured Personnel Carriers were fitted with .50 cals for Vietnam and the guns have been in constant NZ service since.”


Frankford developed the rimless round to the required ballistics and the cartridge was adopted on 12 May 1919 as the Calibre .50 ball cartridge, Model of 1919. Work continued on perfecting the gun’s design, including the hydraulic buffer assembly and the familiar spade handle grips, with the first official Government test occurring on 26 October 1920.


During tests the prototype gun fired just over 2000 rounds and the results were judged to be satisfactory with only a few minor changes needed for quantity manufacture to begin. The first test was followed by a 10,000 round endurance test which took into account the rounds already fired by the gun. While the prototype gun was water-cooled, air-cooled aircraft and tank models were also developed.


Model Overall length Barrel length Weight of bare gun Rate of fire
M2 w/cooled 65.93 inch 45 inch 100.5 lbs 550-650 rpm
M2 Heavy Bbl 65 inch 45 inch 84 lbs 400-500 rpm
M2 Aircraft 56.125 inch 36 inch 64 lbs 650-750 rpm


The US Government consequently ordered 20 guns from Colt consisting of five air-cooled aircraft guns, three water-cooled guns, and two air-cooled tank guns with the remaining 10 guns to be in a configuration decided later. A 10,000 gun order was proposed but not actioned due to severe defence budget cuts following WW1.


Work continued on improvements to the guns at the Colt plant and marketing trips were made overseas to many foreign governments. Despite these efforts, sales of the gun by Colt to all markets between 1921 and 1939 only totalled 11,013 guns, of which 9,942 were purchased by the US Government. The year 1939, however, was about to usher in a whole new market!



The outbreak of WW2 brought urgent interest from Great Britain in .50 Brownings, having been familiar with them from pre-war marketing by Colt’s UK agents, Armstrong Whitworth & Co Ltd. Also the RAF had decided on the .303 Mk II Browning machine guns as standard fighter armament in 1934.


The subsequent decision of the RAF to mount eight .303 Browning Mk II guns in the Hurricane and Spitfire fighters was an inspired choice and the principal cause of Britain’s victory in the Battle of Britain. Thus, Britain was well aware of the reliability of the Browning guns, and also of the need for more hitting power.


Many of the General Motors divisions were contracted to produce the .50 cal, including AC Spark Plugs and Frigidaire.


The British Purchasing Commission contracted the High Standard manufacturing Company, and the Kelsey-Hayes Wheel Company to each provide 12,000 .50 M2 Aircraft Guns as soon as possible. Neither company was yet manufacturing and needed to tool up and get all the manufacturing details from Colt under licence.


During this time the US Government had not been idle and had come up with an integrated manufacturing plan for the .50 Browning, as well as all the other weapons and items required for war. This plan called for eight contractors to manufacture the guns, only three of whom had any firearms experience, namely Colt’s Patent Firearms Company, High Standard Manufacturing Company, and Savage Arms Corporation.


“The .50 cal round is a deadly destroyer of vehicles - a single hit will wreck an engine block, a transmission, or a differential... the projectiles also go straight through large diameter tree trunks and concrete block walls...”


The other five were manufacturers of car parts and household appliances. These were Kelsey-Hayes Wheel Company, Buffalo Arms Corporation (a subsidiary of car parts manufacturer Houdaille-Hershey Corporation), Brown-Lipe-Chapin, Frigidaire, and AC Spark Plug, all divisions of General Motors Corp.


The following chart shows the incredible WW2 production of the various .50 Browning models that were made by these eight companies, bearing in mind that they were also heavily involved in other war work.


*Wing-mounted aircraft models were fixed in position, whereas the flexible models were able to be tilted and swiveled. Some readers of this list may well find that they have a Flexible Heavy Barrel gun by Frigidaire, for example, in their collection even though Frigidaire never produced that model.


Colt’s Patent         
FA Co 169,226 18,429 53,047 240,702
High Standard Mfg 306,716 18,720 9,346 334,782
Savage Arms Corp 295,361     295,361
Kelsey-Hayes 108,640     108,640
Buffalo Arms         
Corp 84,350     84,350
Chapin 119,789     119,789
Division 345,823   16,977 362,800



The reason for this is that the receiver and working parts of the gun were of a common design and the various barrel and jacket combinations could be freely interchanged by armourers to suit their needs at the time. Additionally, a great many .50 M2 guns were arsenal rebuilt in the years following the war, a practice that continues to this day.


As the chart shows, the vast majority (almost 78%) of the guns built were aircraft models. The reason for this was that huge numbers of aircraft were built during the war, a very high number of which were lost, both in combat and training. As an example, American aircraft combat losses in the European Theatre of Operations totalled 10,561 planes.


The shooting down of bombers like the B17 (13 guns), B24 (10 guns), P47 (8 guns), P38 fighter (4 guns), and P51 Mustang (6 guns) resulted in the loss of 106,276 .50 cal M2 machine guns.


Add to that training accidents and combat losses in the other theaters of the war, and then the losses of the other Allies, and the need for the vast number of aircraft guns becomes obvious.

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The total cost of WW2 production was US$472,880,000 which works out to an average of $252.81 per gun. Today’s equivalent price would be about US$3,600 but the actual price of modern-made .50 Browning machine guns is about US$15,000 per gun, because that they are not being made in anywhere near the volume of WW2 production, and of course in wartime the government imposed severe profit margins on the manufacturers.



As mentioned above, the principal use of the .50 M2 was in aircraft but the next most numerous model was the M2 Heavy Barrel which was employed mainly as a vehicle gun.


All US armoured vehicles from the M3A1 Scout Car through to main battle tanks were equipped with at least one .50 M2 HB as a flexible commander’s gun, in addition to .30 cal Brownings in both fixed and flexible roles.


Over-cab ring mounts were also fitted to a great many trucks and half-tracks, while the ubiquitous Jeep frequently had a pedestal mount behind the seats that could mount either the .50 or .30 Brownings. All these vehicles also carried M3 tripods so the guns could be taken off the vehicles and fired from the ground when required.


The Browning .50 cal has been in continuous service with the armies of the West for 92 years, and no one has plans for replacing them any time soon... (Photo: “Small Arms from 1860 to the Present Day” by Martin J. Dougherty.


The M16 half-track was fitted with the 4-gun Maxson motorised mount that allowed rapid 360º rotation with elevation from below horizontal to almost vertical, and was mainly used for anti-aircraft work. When used against ground targets, generally in support of an attack, the results were devastating.


The “Quad .50”, as the Maxson mount was colloquially known, was also mounted on the M45 trailer which could be towed by any Allied vehicle, and was usually used on jacks with the wheels removed, but could be fired on its wheels in an emergency.


The Long Range Desert Group, and later the Special Air Service, made extensive use of .50 M2 aircraft Brownings on their vehicles where the destructive firepower proved invaluable on their many “hit & run” raids.


“The speed of aircraft increased considerably as the war progressed and the opportunities for shooting at an enemy plane were very fleeting, therefore it was necessary to get as much lead in the air as possible during these encounters.”


The aircraft Brownings were preferred over the M2 HB for two reasons - first being their ready availability from the RAF in the Middle East (frequently salvaged from plane wrecks), and secondly, their increased rate of fire (550-650 rounds per minute as opposed to 400-500 for the HB).


The water-cooled guns were primarily used by the US Navy as anti-aircraft defence on their ships. If you study photographs of US aircraft carriers you will see that they bristled with them just below the level of the flight deck, frequently in tandem mounts. The other main use for the water-cooled guns was as anti-aircraft defence around bases and airfields, often in conjunction with HB Quad .50 guns.


Although the M2 Aircraft model had a rate of fire of about 10 rounds per second, the ideal rate for aerial warfare was double that. The speed of aircraft increased considerably as the war progressed and the opportunities for shooting at an enemy plane were very fleeting, therefore it was necessary to get as much lead in the air as possible during these encounters.


“The .50 cal round is a deadly destroyer of vehicles - a single hit will wreck an engine block, a transmission, or a differential... the projectiles also go straight through large diameter tree trunks and concrete block walls...”


Work had been ongoing throughout the war on this project and in 1945 the M3 Aircraft gun was adopted. The guns was developed on the standard M2 body but had a much lighter bolt of special high-strength steel, a much more robust rear buffer, and other modifications.


The M3 was reasonably reliable and had a cyclic rate of 1150-1250 rounds per minute but only 2,000 guns were delivered before the war ended. All manufacture of the .50 M2 guns ceased in 1945, with the exception of the M3 Aircraft gun which continued to about 1953.



The Korean War saw the .50 M2 back in all its usual roles but the M3 programme was lagging behind the needs of the Air Force, consequently, orders were placed with Colt (10,000 guns), Savage (parts only) and two new players; Saco-Lowell (10,000 guns), and Wayne Pump (10,000 guns). Springfield Armory also converted over 10,000 M2’s to M3’s over this period. The M3 was dropped from use in the late 1950’s, by which time aerial gunnery was giving way to missiles.


Vietnam became the next event that required the use of the .50 M2 guns, once more in their traditional roles, although two new platforms made extensive use of the guns - the US Navy River Boat squadrons, and the large number of M113 Armoured Personnel Carriers. All of the New Zealand M113 APC’s were fitted with M2 HB’s at this time and the gun has been in constant NZ service since.


All of the guns used in Vietnam were made during WW2 and by the late 1970’s it became necessary to begin manufacture again to make up the shortfall that had occurred over the previous 32 years. This shortfall was not only due to losses in Korea and Vietnam but also that the guns had been adopted by most Western nations, provided from US stocks.


John Browning designed the .50 cal in 1918 and like most things he did, he got it right the first time.


The first US contract for new production was Saco Defense Systems in 1977 (now owned by General Dynamics and still in production) closely followed by ERMCO (E R Maples Co, subsequently sold to RAMO in 1984). RAMO had been rebuilding old M2’s for export when they got their first US manufacturing contract and have since introduced several variations to the basic design.


The FN factory in Belgium has been manufacturing the M2 for European customers since the late 1940’s and production is ongoing. The UK company of Manroy Engineering began producing spare parts for the British military in 1975 and began manufacture of the M2 in 1980, while the Korean Tong Il Company (now part of Samsung) also makes the gun.


One of the few problems with the M2 Browning was the adjustable headspace system which meant the gun had to have the headspace checked and adjusted as part of the normal firing routine.


The modern manufacturers have addressed this and now they all offer fixed-headspace QCB (Quick Change Barrel) systems which are all variations of a theme but not interchangeable. The standard M2 guns are still being manufactured and are the most numerous, although the QCB models are becoming more popular.



The method of operation of the M2 Browning is essentially identical to that of its parent, the M1917 Browning. It is recoil operated with the barrel, barrel extension, and breechblock moving rearward about 30mm after firing, at which point the locking block is disconnected from the breech block by a cam. As the breechblock begins to move rearward from the recoil, the extractor pulls the next round from the belt.


As the breechblock continues rearward with its own inertia, it is given a flick by the accelerator fingers on the buffer. This imparts enough energy for the breechblock to continue completely to the rear, compressing the return spring. During this travel, the feed arm is actuated by a cam slot in the top of the breech block and the next cartridge is moved into position in the feedway.


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The last part of the rearward travel and the first part of the return activates cams on the extractor which slide the cartridge down the breech face to align with the chamber, this action forcing the fired case down and out of the bottom of the gun.


As the breechblock chambers the round and makes contact with the barrel extension, the whole group moves forward 30mm again and the locking block is cammed into the breechblock. At the same time the extractor is cammed back up to grip the next round in the belt.


The gun can be belt-fed from either the right or left side, a change that takes only minutes. The spade handle grips are a .50 cal trademark. A spare barrel, along with headspace and timing gauges and cleaning gear can be seen in this firing position. There’s also an M1 carbine close at hand.


If the trigger is still depressed, the gun will fire and the cycle will be repeated. If the trigger has been released then the striker will remain cocked, ready for the next press of the trigger.


During the rearward travel of the breechblock a cocking lever engages a slot in the top of the receiver and draws the striker to the cocked position where it is held by the sear.


“The Saboted Light Armour Piercing (SLAP) rounds will penetrate 3/4” (19mm) of armour at 1500 yards...”


Although this sequence of events sounds complex, it is actually quite simple and reliable, especially when compared to the operation of some other machine guns!


Among the many desirable features of Browning .50 cal is its ability to be belt-fed from either left or right, a change that takes only minutes, which makes it very versatile for multiple gun mounts and cramped conditions (tank turrets, aircraft wings, etc).



The first ‘Cartridge, Ball, Calibre .50, M1923’ had a steel-cored bullet and was capable of penetrating 5/8” (16mm) of armour at 500 yards (455 metres). A tracer round was also developed about the same time. Prior to WW2 little more development was done but the war soon changed that situation.


By the end of WW2 the following types were in use:

Ball, M2 Armour Piercing, M2 Tracer, M2, M10, M17, M21 (day, night, and different ranges) Armour Piercing, Incendiary, M8, M20, M23 (tracer, and various compounds for harder to ignite fuels) US WW2 production of these types exceeded 640 million rounds at an average price of US 11 cents each.


Since the war there have been various new types of .50 Browning ammunition developed including the Saboted Light Armour Piercing (SLAP) rounds which have a tungsten penetrator that will penetrate 3/4” (19mm) of armour at 1500 yards (1365 metres).


A .50 BMG cartridge compared to a .30/06 and a 12 gauge shotshell.


One of the most significant recent advances has been in the development of .50 cal long-range sniping ammunition and rifles which are capable of hits on man-sized targets at ranges in excess of 2,500 metres.


The Norwegian Raufoss company has developed their Mk 211 round which is Armour Piercing, Explosive, Incendiary, and is proving to be accurate and very effective for long-range use. It has been adopted by the US and other nations and is made under licence by several manufacturers.



The M2 Browning is seeing a resurgence of deployment by virtually all western nations, including New Zealand where it is being introduced as an infantry support weapon in addition to its role as a vehicle-mounted gun. The gun is also used on most Royal New Zealand Navy vessels.


There have been several attempts to fit telescopic sights to the M2, taking advantage of the dovetail originally provided for the M1 Telescopic sight developed in 1936, but made obsolete by 1941.


The rare M1 telescopic sight, developed in 1937 and obsolete by 1941.


The most notable case of scope use was in Vietnam where the legendary US sniper, Carlos Hathcock, achieved a kill at over 2,000 yards with a tripod mounted M2 HB. Many modern guns are now fitted with night vision devices.


The development of specialist sniping rifles in .50 BMG calibre has most countries now setting up special purpose long-range sniping teams within their existing sniping units.


Afghanistan has proven to be an environment where these teams are particularly effective in the mountainous terrain, neutralising targets which would normally be able to evade conventional airborne and vehicle weaponry.


“The .50 Browning Machine Gun in any configuration is a desirable collector’s item today throughout the world, and a small number exist in NZ collections.”


Like virtually all of John Browning’s designs, the .50 M2 Browning Machine Gun is destined for a long future that will definitely exceed one hundred years. This is a fantastic testament to a man who had only basic schooling, but had a grasp of engineering and firearm design that has never been surpassed.


The .50 Browning Machine Gun in any configuration is a desirable collector’s item today throughout the world, and a small number exist in NZ collections.


Because of the demand from modern militaries, and the ability to rebuild the basic receivers almost ad infinitum, the price of these collector guns has always remained high and, with the limited supply, is likely to remain so for the forseeable future.



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