Feat of the Week: Browning M2 Machine Gun
The Gunsmithing Story
One of our customers asked us to come to his property and service his two Browning M2 machine guns. We don’t often make house calls. But for these two M2s, we obliged.
When we arrived, we found the two machine guns mounted on vehicles. They had been sitting there for three years without being touched—both no longer had any oil and were full of rust. One was completely inoperable and the other was very stiff.
We began by removing them from the mounts. It took quite a bit of time to get them safely down. They are difficult to handle and carry because each M2 weighs 84 pounds. Once they were unmounted, we removed the barrel assembly—weighing about 30 pounds—to make transportation easier.
We brought them back to the shop to clean. Each M2 spent time in the Ultrasonic cleaner and got a new coat of oil. We also scrubbed all of the rust from them both. After removing the rust and cleaning the M2s, we tuned them to shoot properly.
First, we fixed the headspace—the distance from the chamber feature limiting the cartridge insertion depth to the closed breech face. If the headspace is too small, the gun won’t chamber, or if it is too large, the gun could explode. To adjust the headspace on the M2, we screwed the barrel in or out to the proper distance. Using a .50 BMG go/no go gauge, we made sure we gave these M2s the proper headspace.
Next, we tuned the spring tension on the bolt to make sure the system moved back far enough to both eject and load the next round.
Completing all the work on both of these Browning machine guns was an all day affair. But when we were finally finished, we headed to Albany Pistol and Rifle Club to make sure they functioned properly.
Browning M2 History
Popularly known as “Ma Deuce,” this .50 caliber heavy machine gun has been in use longer than any other firearm in the U.S. military—except the M1911 which was also developed by Browning. And, as the longest produced machine gun, the M2 has seen action in almost every conflict from the Second World War to the War in Afghanistan. It has been used as a vehicle, aircraft, and boat weapon as well as for infantry support and as a sniper rifle.
The M2 was designed by Browning near the end of the First World War when the Germans created the Junkers armored plane. Because this new aircraft was immune to standard rifle calibers of the time, General Pershing submitted a request for a larger caliber and machine gun.
By Richard C. Wysong II - http://en.wikipedia.org/wiki/Image:Rifle_cartridge_comparison.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1419003
.50 BMG compared to 300 Win Mag, .308 Winchester, 7.62x39mm, 5.56 NATO, and .22 LR (Left to Right)
Browning began working on the request and used the M1917 (the precursor to the M1919) as the foundation of his new design. While Browning developed the gun, Winchester worked on creating a .50 caliber cartridge to match.
Trials of the first iteration occurred in 1918 but had several issues. It was extremely heavy, difficult to control, and it wasn’t effective against armor.
Luckily, around the same time, the military had acquired some German anti-tank rifles and ammunition. Winchester used these German armaments to refine and improve their .50 caliber round which eventually became known as .50 BMG (which stands for Browning Machine Gun).
Browning and his colleague Fred Moore also continued to improve their design and began trials of the M1921—the water-cooled predecessor of the M2—which was used from 1921 to 1937. But the design still wasn’t perfect, and unfortunately, Browning died during the interwar years without a refined version of his .50 caliber machine gun.
Soldier using a Browning M2HB during exercises
By Photographer’s Mate 2nd Class Michael Sandberg, USN - This image was released by the United States Navy with the ID 021108-N-4374S-063. Public Domain, https://commons.wikimedia.org/w/index.php?curid=2160669
After his death, S.H. Green began working on improvements to the M1921. Most importantly, to eliminate weight, the water-cooling system was removed in favor of an air-cooled, heavier barrel.
Colt manufactured several of these machine gun prototypes, and in 1933, began producing the newer and better version of the M19121.
With an improved design, this iteration became known as the Browning M2HB (which stands for heavy barrel). These machine guns shoot 450 to 600 rounds per minute (aircraft M2s shoot at a much higher rate) and have an effective range up to 2,000 yards.
FN, the company at which Browning finished his career, also began manufacturing the M2, and they still continue to make them to this day.
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