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Rifle cartridge designed by John Moses Browning From Wikipedia, the free encyclopedia
The .50 BMG (.50 Browning Machine Gun), also known as 12.7×99mm NATO, and designated as the 50 Browning by the C.I.P.,[2] is a .50 in (12.7 mm) caliber cartridge developed for the M2 Browning heavy machine gun in the late 1910s, entering official service in 1921. Under STANAG 4383, it is a standard service cartridge for NATO forces. The cartridge itself has been made in many variants: multiple generations of regular ball, tracer, armor-piercing (AP), incendiary, and saboted sub-caliber rounds. The rounds intended for machine guns are made into a continuous ammunition belt using metallic links.
.50 BMG | ||||||||||||||||||||||||
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Type | Anti-materiel rifle, heavy machine gun | |||||||||||||||||||||||
Place of origin | United States | |||||||||||||||||||||||
Service history | ||||||||||||||||||||||||
In service | 1921–present | |||||||||||||||||||||||
Used by | NATO | |||||||||||||||||||||||
Wars | World War II Korean War Vietnam War Cambodian Civil War Falklands War Persian Gulf War The Troubles Global War on Terrorism Iraq War War in Afghanistan Mexican drug war Syrian Civil War Iraqi Civil War (2014–2017) Yemeni Civil War (2015–present) Saudi Arabian-led intervention in Yemen Saudi–Yemeni border conflict (2015–present) Sri Lankan Civil War 2022 Russian invasion of Ukraine | |||||||||||||||||||||||
Production history | ||||||||||||||||||||||||
Designer | Winchester Repeating Arms Co. and Frankford Arsenal | |||||||||||||||||||||||
Specifications | ||||||||||||||||||||||||
Parent case | .30-06 Springfield | |||||||||||||||||||||||
Case type | Rimless, bottleneck | |||||||||||||||||||||||
Bullet diameter | 12.98 mm (0.511 in) | |||||||||||||||||||||||
Land diameter | 12.65 mm (0.498 in) | |||||||||||||||||||||||
Neck diameter | 14.22 mm (0.560 in) | |||||||||||||||||||||||
Shoulder diameter | 18.14 mm (0.714 in) | |||||||||||||||||||||||
Base diameter | 20.42 mm (0.804 in) | |||||||||||||||||||||||
Rim diameter | 20.42 mm (0.804 in) | |||||||||||||||||||||||
Rim thickness | 2.26 mm (0.089 in) | |||||||||||||||||||||||
Case length | 99.31 mm (3.910 in) | |||||||||||||||||||||||
Overall length | 138.43 mm (5.450 in) | |||||||||||||||||||||||
Case capacity | 292.8 cm3 (4,519 gr H2O) | |||||||||||||||||||||||
Primer type | #35 Arsenal Primer | |||||||||||||||||||||||
Maximum pressure (TM43-0001-27) | 378.68 MPa (54,923 psi) | |||||||||||||||||||||||
Maximum pressure (EPVAT) | 417.00 MPa (60,481 psi) | |||||||||||||||||||||||
Maximum pressure (C.I.P.) | 370.00 MPa (53,664 psi) | |||||||||||||||||||||||
Ballistic performance | ||||||||||||||||||||||||
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Test barrel length: 45 in (1,100 mm) Source(s): Ammoguide.com [2] |
The .50 BMG cartridge is also used in anti-materiel rifles. A wide variety of ammunition is available, and the availability of match grade ammunition has increased the usefulness of .50 caliber rifles by allowing more accurate fire than lower-quality rounds.[3]
In response to the need for new anti-aircraft weaponry during World War I, John Browning developed the .50 BMG. He wanted the round to be used in a machine gun based on a scaled-up version of the M1917 Browning.[4]
The development of the .50 BMG round is sometimes confused with the German 13.2 mm TuF, which was developed by Germany for an anti-tank rifle to combat British tanks during World War I and against aircraft. According to American Rifleman: "Actually, the Browning .50 originated in the Great War. American interest in an armor-piercing cartridge was influenced by the marginal French 11 mm (0.43 in) design, prompting U.S. Army Ordnance officers to consult Browning. They wanted a heavy projectile at 2,700 ft/s (820 m/s), but the ammunition did not exist. Browning pondered the situation and, according to his son John, replied, 'Well, the cartridge sounds pretty good to start. You make up some cartridges and we'll do some shooting.'"[5]
The American Rifleman further explains that development was "[r]eputedly influenced by Germany's 13.2x92 mm SR (.525 in) anti-tank rifle" and that then "Ordnance contracted with Winchester to design a .50-cal. cartridge. Subsequently, Frankford Arsenal took over from Winchester, producing the historic .50 BMG (12.7×99 mm) cartridge. The Army then returned to John Browning for the actual gun. Teamed with Colt, he produced prototypes ready for testing and, ironically, completed them by Nov. 11, 1918—the Great War's end."[5]
The round was put into use in the M1921 Browning machine gun. This gun was later developed into the M2HB Browning, which, with its .50 caliber armor-piercing cartridges, went on to function as an anti-aircraft and anti-vehicular machine gun, capable of penetrating 0.9 inches (23 mm) of face-hardened armor steel plate at 200 meters (220 yd),[6] 1 inch (25 mm) of rolled homogeneous armor at the same range,[7] and 0.75 inches (19 mm) at 547 yards (500 m).[8]
During World War II the .50 BMG was primarily used in the M2 Browning machine gun, in both its "light barrel" aircraft mount version and the "heavy barrel" (HB) version on ground vehicles, for anti-aircraft purposes. An upgraded variant of the M2 Browning HB machine gun used during World War II is still in use today. Since the mid-1950s, some armored personnel carriers and utility vehicles have been made to withstand 12.7 mm machine gun fire, restricting the destructive capability of the M2. It still has more penetrating power than lighter weapons such as general-purpose machine guns, though it is significantly heavier and more cumbersome to transport. Its range and accuracy, however, are superior to light machine guns when fixed on tripods, and it has not been replaced as the standard caliber for Western vehicle-mounted machine guns (Soviet and CIS armored vehicles mount 12.7×108mm NSVs, which have similar dimensions to .50 BMGs).
Decades later, the .50 BMG was chambered in high-powered rifles as well.[4] The Barrett M82 rifle was developed during the 1980s and, along with later variants, has upgraded the anti-materiel power of the military sniper.[4]
The primary military use of this round is in the M2 Browning machine gun and anti-materiel rifles such as the Barrett M82.[9]
The U.S. Coast Guard uses .50 BMG rifles onboard armed helicopters to disable the engines on boats during interdictions. Similarly, .50 BMG weapons have attracted attention from law enforcement agencies; they have been adopted by the New York City Police Department as well as the Pittsburgh Police. A .50 BMG round can effectively disable a vehicle when fired into the engine block. A .50 BMG round will penetrate most commercial brick walls and concrete cinder blocks.[citation needed]
The .50 BMG round was used as a sniper round as early as the Korean War.[10] The former record for a confirmed long-distance kill was set by U.S. Marine sniper Carlos Hathcock in 1967 during the Vietnam War, at a distance of 2,090 meters (2,290 yd; 1.30 mi);[11] Hathcock used the .50 BMG in an M2 machine gun equipped with a telescopic sight. This weapon was used by other snipers, and eventually purpose-built sniper rifles were developed specifically for this round.[12]
In June 2017, a McMillan TAC-50 was used by a sniper with Canada's Joint Task Force 2 to kill an Islamic State insurgent in Iraq, setting the new world record for the longest confirmed kill shot in military history at 3,540 meters (3,870 yd; 2.20 mi).[13] Before that, a British sniper in Afghanistan held the record at 2,475 meters (2,707 yd; 1.538 mi) using an Accuracy International AWM L115A3 long-range rifle chambered for .338 Lapua Magnum (8.58×70 mm) rounds.[14][15]
In addition to long-range and anti-materiel, the U.S. military uses .50 BMG weapons to detonate unexploded ordnance from a safe distance. It can disable most unarmored and lightly armored vehicles.[16]
Some civilians use .50 caliber rifles for long-range target shooting: the US-based Fifty Caliber Shooters Association holds .50 BMG shooting matches.[17]
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The .50 BMG (12.7×99mm NATO) cartridge has a capacity of 290 gr (19 g). The round is a scaled-up version of the .30-06 Springfield but uses a case wall with a long taper to facilitate feeding and extraction in various weapons.
The common rifling twist rate for this cartridge is 1 in 15 in (380 mm), with eight lands and grooves. The primer type specified for this ammunition is a boxer primer that has a single centralized ignition point (US and NATO countries).[18] However, some other countries produce the ammunition with Berdan primers that have two flash holes.
The average chamber pressure in this round as listed in TM43-0001-27,[19] the U.S. Army Ammunition Data Sheets — Small Caliber Ammunition, not including plastic practice, short cased spotter, or proof/test loads, is 54,923 psi (378,680 kPa). The proof/test pressure is listed as 65,000 psi (450,000 kPa).
A common method for understanding the actual power of a cartridge is comparison of muzzle energies. The .30-06 Springfield, the standard caliber for American soldiers in both World Wars and a popular caliber amongst American hunters for medium to large game animals, can produce muzzle energies between 2,000 and 3,000 foot-pounds force (3,000 and 4,000 J). The .50 BMG round can produce between 10,000 and 15,000 foot-pounds force (14,000 and 20,000 J), depending on its powder and bullet type, as well as the weapon it is fired from. Due to the high ballistic coefficient of the bullet, the .50 BMG's trajectory also suffers less "drift" from crosswinds than smaller and lighter calibers, making the .50 BMG a good choice for high-powered sniper rifles.[20]
The .50 BMG cartridge is also produced commercially in a wide range of specifications, including armor-piercing, tracing, and incendiary:[21]
DARPA (Defense Advanced Research Projects Agency) contracted with Teledyne Scientific Company to develop the EXACTO program, including a .50-caliber guided bullet. Videos published by DARPA show the guided bullet diverting to strike a moving target.[29][30][31][32]
Three distinct and non-compatible metallic links have been used for .50 BMG cartridge belts. The M2 and M9 links, "pull-out" designs, are used in the Browning M2 and M3 machine guns.[33][34] The M15-series metal "push-through" links were used in the M85 machine gun. Pull-out cloth belts were also used at one time but have been obsolete since 1945.
Within the United Kingdom, it is legal to own a bolt action .50 BMG rifle with a section 1 Firearms Certificate.[35] Applications requesting firearms in this caliber are assessed by the same criteria as smaller calibers; with the applicant having to prove they have a valid reason for owning such a weapon.[36]
The specified maximum diameter of an unfired .50 BMG bullet is 0.510-inch (13.0 mm); while this appears to be over the .50 inch (12.7 mm) maximum allowed for non-sporting Title I firearms under the U.S. National Firearms Act, the barrel of a .50 BMG rifle is only .50 inch (12.7 mm) across the rifling lands and slightly larger in the grooves. The oversized bullet is formed to the bore size upon firing, forming a tight seal and engaging the rifling. Subject to political controversy due to the great power of the cartridge (it is the most powerful commonly available cartridge not considered a destructive device under the National Firearms Act), it remains popular among long-range shooters for its accuracy and external ballistics. While the .50 BMG round is able to deliver accurate shot placement (if match grade ammunition is used) at ranges over 1,000-yard (910 m), smaller-caliber rifles produce better scores and tighter groups in 1,000-yard (910 m) competitions.[37]
A 1999 Justice Department Office of Special Investigations briefing on .50 caliber rifle crime identified several instances of the .50 BMG being involved in criminal activities. None of the cited cases has confirmed domestic violent criminal use of a .50 BMG firearm, and a majority of the domestic cases were possession charges.[38]
In the United States, Washington, D.C. disallows registration of .50 BMG rifles, thus rendering civilian possession unlawful.[39][40] California prohibits the private purchase of a rifle capable of firing the .50 BMG through the .50 Caliber BMG Regulation Act of 2004.[41] Connecticut specifically bans the Barrett 82A1 .50 BMG rifle.[42] However, .50 BMG rifles registered prior to the enacted bans remain lawful to possess in California[40][43] and Connecticut.[40][44] In Illinois, it is legal to possess a .50 caliber rifle only if it was acquired by January 10, 2023, and it was registered with the state police by January 1, 2024.[45] Maryland imposes additional regulations on the sale and transfer of .50 BMG rifles and other "regulated firearms", and limits purchases of any firearm within this class to one per month, but does not impose registration requirements or any form of categorical ban.[40]
Contrary to a persistent misconception within the United States Armed Forces, using .50 BMG directly against enemy personnel is not prohibited by the laws of war.[46] Writing for the Marine Corps Gazette, Major Hays Parks states that "No treaty language exists (either generally or specifically) to support a limitation on [the use of .50 BMG] against personnel, and its widespread, longstanding use in this role suggests that such antipersonnel employment is the customary practice of nations." Parks theorizes that the misconception originated in historical doctrine discouraging the use of the M8C spotting rifle—an integral .50-caliber aiming aid for the M40 recoilless rifle—in the antipersonnel role. This limitation was entirely tactical in nature and was intended to hide the vulnerable M40 and its crew from the enemy until the main anti-tank gun was ready for firing; however, Parks concludes that some U.S. troops assumed the existence of a legal limitation on the use of .50-caliber projectiles more generally.