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John Browning’s Aerial Equalizer: Ma Deuce

John Browning’s Aerial Equalizer: Ma Deuce

By Barrett Tillman

In 1966, novelist Robert Ruark wrote a nonfiction book about hunting in Africa. It was titled Use Enough Gun—good advice for everyone, especially in aerial combat. When the world’s air arms used mixed machine gun and cannon armament for fighters, and mostly rifle-caliber guns on bombers, the United States took another route. The original P-36, P-39, and P-40 series had a mixture of Browning .30 and .50 caliber guns while the P-38 upped the ante with four .50s and a 20mm. But, by 1943, the standard U.S. fighter armament was four or six .50s, increasing to an eye-watering eight in the P-47. In any case, the classic “Ma Deuce” from the fertile mind of John M. Browning ruled supreme.

Browning was the Mormon genius behind many of America’s most important military firearms. He designed the M1911 pistol (still in use today), the 1918 Browning Automatic Rifle (used through Korea), and the belt-fed M1917 water-cooled and M1919 air-cooled machine guns. This was in addition to his fabulous .50 Cal. The only other individual who invented a significant U.S. military arm of WW II was Canadian-born John C. Garand of Army Ordnance and his U.S. Rifle Cal .30 M-1.

The recoil-operated M2 Browning (originally produced by Colt) fired a nominal 700-grain bullet (1/10 pound) at 2,800 feet per second. (A typical .30 cal. round was 150 grains at comparable velocity.) The M2’s standard rate of fire was 800 rounds per minute or about 13 per second—times four, six, or eight, produced an awesome amount of lead on target, capable of shredding a single-engine aircraft in a few seconds. Four .50s delivered more than twice the weight of fire as the RAF’s eight .303s in the same amount of time.

Though Browning’s original .50 design was tested in 1918, he refined it thereafter. The result was a water-cooled ground mount adopted as the M1921. Development continued after Browning’s death, and the U.S. Navy adopted the now-familiar configuration in 1933. It was the aircraft weapon that defeated Axis air forces.

The big .50 slug carried enormous authority at long range. At 500 yards, the M2 ball would punch through 1/3-inch vertical armor plate, armor-piercing rounds penetrated three-quarter inch steel, and armor-piercing incendiary defeated a 0.63-inch plate. Most .30 or 7.62mm rounds would only dimple hardened steel at that distance. Many .30-06 rounds would not defeat a half-inch mild steel plate at 100 yards.

With its relatively high rate of fire, the .50 BMG could rip up a target like the proverbial can opener. At 13 rounds per second, with a 2,800 fps velocity, each round after the first one presumably followed by 215 feet.

In both turrets and “free” mounts, the M2 armed every Army Air Force bomber during the war. Ten Brownings were standard on B-17Gs: four twin turrets (nose, top, belly, and tail) plus two hand-held guns in the waist.

During WW II, the improved M3 featured a higher rate of fire, approximately 1,200rpm, often in the anti-aircraft role. In the jet age, M3s became standard, as faster subsonic speeds meant less time to track many targets.

With more than 3 million produced over 90 years, today “Ma Deuce” continues in service around the world. It’s still an aircraft gun, arming some helicopters and occasionally fixed-wing aircraft.

Updated: February 28, 2013 — 12:03 PM
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  1. Barrett does it again! Another good look at a great design!!!! Way to go!…. No ‘FRILLS”, just the fact’s Ma’am!

  2. More than half of the B-17’s produced were the G model. most of them had 13, 50 caliber Brownings. Besides the positions mentioned in this fine article there were 2 Cheek guns, and one that the Radio Operator operated out of the top hatch.

  3. There was at least one variation on this theme. In the early ’50s the RAAF (Royal Australian Air Force) operated a Commonwealth Aircraft Corporation (CAC)-modified version of the NA F-86 “Sabre” by replacement of the 6×50-cal MG’s with 2x30mm Aden cannon. The GE J-47 engine was also changed to a Rolls-Royce “Avon” RA-7 turbojet. With several other modifications to fuselage and wings the result was dubbed the “Avon Sabre” Mks. 30-32.

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