.50 BMG Cartridge
.50 BMG Cartridge
Type Rifle Place of origin United States of America
In service 1914–present
Used by NATO and many others Wars WWI, WWII, Korean War, Vietnam War, Cambodian Civil War, Falklands war, Gulf War, War on Terror, Iraq War
Designer John Browning
Bullet diameter 0.51 in (13.0 mm)
Neck diameter 0.56 in (14.2 mm)
Shoulder diameter 0.741 in (18.8 mm)
Base diameter 0.804 in (20.4 mm)
Rim diameter 0.804 in (20.4 mm)
Case length 3.91 in (99 mm)
Overall length 5.45 in (138 mm)
Primer type #35 Arsenal Primer
Bullet weight/type Velocity Energy
647 gr (41.9 g) Speer 3,044 ft/s(928 m/s) 13,144 ft·lbf (17,821 J)
655 gr (42.4 g) ADI 3,029 ft/s (923 m/s) 13,350 ft·lbf (18,100 J)
700 gr (45 g) Barnes 2,978 ft/s (908 m/s) 13,971 ft·lbf (18,942 J)
750 gr (49 g) Lapua 2,618 ft/s (798 m/s) 11,419 ft·lbf (15,482 J)
800 gr (52 g) Barnes 2,895 ft/s (882 m/s) 14,895 ft·lbf (20,195 J)
Test barrel length: 45 in (1143 mm)
The .50 Browning Machine Gun (12.7x99mm NATO) or .50 BMG is a cartridge developed for the Browning .50 Caliber machine gun in the late 1910s. Entering service officially in 1921, the round is based on a greatly scaled-up .30-06 cartridge. The cartridge itself has been made in many variants: multiple generations of regular ball, tracer, armor piercing, incendiary, and saboted sub-caliber rounds. The rounds intended for machine guns are linked using metallic links.
The .50 BMG cartridge is also used in long-range target and sniper rifles, as well as other .50 machine guns. The use in single-shot and semi-automatic rifles has resulted in many specialized match-grade rounds not used in .50 machine guns. A McMillan Tac-50 .50 BMG sniper rifle was used by Canadian Corporal Rob Furlong to bring off the longest-range confirmed sniper kill in history, when he shot a Taliban insurgent at 2,430 meters (2,657 yards) during the 2002 campaign in Afghanistan.
The previous record for a confirmed long-distance was set by US Marine sniper Carlos Hathcock in 1967, the distance was 2,286 meters (2,500 yards) or 1.42 miles (2.29 km). Hathcock used the same round in an M2 Browning Machine Gun equipped with a telescopic sight. This weapon was used by other snipers, and eventually purpose-built sniper rifles were developed especially for this round. The previous standard for ammunition for sniper rifles was .30-06, but the .50 round is more accurate at extreme range.
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.
The round was conceptualized during World War I by John Browning in response to a requirement for an anti-aircraft weapon. The round itself is based on a scaled-up .30-06 Springfield design, and the machine gun was based on a scaled-up M1919/M1917 design that Browning had initially developed around 1900 (but which was not adopted by the U.S. military until 1917, hence the model designation). The new heavy machine gun, the Browning M2 .50 caliber machine gun, was used heavily in aircraft, especially during World War II, though its airborne use is limited to helicopters at present. It was and still is used on the ground as well, both vehicle mounted, in fixed fortifications, and on occasion carried by infantry. The incendiary, armor-piercing (AP), armor-piercing incendiary (API), and armor-piercing incendiary tracer (APIT) rounds were especially effective against aircraft, and the AP rounds and API rounds were excellent for destroying concrete bunkers, structures, and lighter AFVs. The API and APIT rounds left a flash, report, and smoke on contact, useful in detecting strikes on enemy targets.
The development of the .50 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 WWI. However, the development of the U.S. .50 round was started before this later German project was completed or even known to the Allied countries. When word of the German anti-tank round spread, there was some debate as to whether it should be copied and used as a base for the new machine gun cartridge. However, after some analysis the German ammunition was ruled out, both because performance was inferior to the modified Springfield .30-06 round and because it was a semi-rimmed cartridge, making it sub-optimal for an automatic weapon. The round's dimensions and ballistic traits are totally different. Instead, the M2HB Browning with its .50 armor-piercing cartridges would go on to function as an anti-aircraft and anti-vehicular machine gun, with a capability of completely perforating 0.875" (22.2 mm) of face-hardened armor steel plate at 100 yards (91 m), and 0.75" (19 mm) at 547 yards (500 m).
Decades later, the .50 BMG would be chambered in high-powered rifles as well. The concept of a .50 machine gun was not an invention of this era; this caliber (.50) had been used in Maxim machine guns and in a number of manual machine guns such as the original Gatling.
During World War II the .50 was primarily used in the M2 Browning machine gun for anti-vehicular and anti-aircraft purposes. An upgraded variant of the M2 Browning machine gun used during World War II is still in use today as the well known M2 machine gun. Since the mid-1950s, some armoured personnel carriers and utility vehicles have been made to withstand 12.7 mm machine gun fire, thus making it a much less flexible weapon. It still has more penetrating power than light machine guns such as general purpose machine guns, though it is significantly heavier and 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 armoured vehicles mount 12.7 mm DShK, NSV, which are ballistically very similar to the .50 BMG, or 14.5 mm KPV machine guns, which have significantly superior armour penetration compared to any 12.7 mm round).
The Barrett M82 .50 Caliber rifle and later variants were born during the 1980s and have upgraded the anti-materiel power of the military sniper. A skilled sniper can effectively neutralize an infantry unit by eliminating several targets (soldiers or equipment) without revealing his precise location. The long range (1 mile+) between firing position and target allows time for the sniper to avoid enemy retribution by either changing positions repeatedly, or by safely retreating.
A common method for understanding the actual power of a cartridge is by comparing muzzle energies. The Springfield .30-06, the standard caliber for American soldiers in World War II and a popular caliber amongst American hunters, can produce muzzle energies between 2000 and 3000 foot pounds of energy (between 3 and 4 kilojoules). A .50 BMG round can produce between 10,000 and 15,000 foot pounds (between 14 and 18 kilojoules) or more, depending on its powder and bullet type, as well as the rifle it was fired from. Due to the high ballistic coefficient of the bullet, the .50 BMG's trajectory also suffers less "drift" from cross-winds than smaller and lighter calibers, making the .50 BMG a good choice for high powered sniper rifles.
The 50 BMG 12.7 x 99 NATO has 290 gr H2O (19 ml) cartridge case capacity. 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.
50 BMG basic cartridge dimensions. All sizes in inches (in). The common rifling twist rate for this cartridge is 1 in 15 in (381 mm), with 8 lands and grooves. The primer type specified for this ammunition is Boxer primer that has a single centralized ignition point (US and NATO countries). However, some other countries produce the ammunition with Berdan primers that have two flash holes., 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 MPa or 3,787 bar). The proof/test pressure is listed as 65,000 psi (448 MPa or 4,482 bar). As a note these are the military machine gun standards and not ideal for use as guidelines in reloading or personal use.
Military cartridge types:
.50 BMG cartridges are also produced commercially with a plethora of different bullets and to a number of different specifications.
Cartridge, Caliber .50, Tracer, M1
Tracer for observing fire, signaling, target designation, and incendiary purposes. This bullet has a red tip.
Cartridge, Caliber .50, Incendiary, M1
This cartridge is used against unarmored, flammable targets. The incendiary bullet has a light blue tip.
Cartridge, Caliber .50, Ball, M2
This cartridge is used against personnel and unarmored targets. This bullet has an unpainted tip .
Cartridge, Caliber .50, Armor-Piercing, M2
This cartridge is used against lightly armored vehicles, protective shelters, and personnel, and can be identified by its black tip.
Cartridge, Caliber .50, Armor-Piercing-Incendiary, M8
This cartridge is used, in place of the armor piercing round, against armored, flammable targets. The bullet has a silver tip.
Cartridge, Caliber .50, Tracer, M10
Tracer for observing fire, signaling, target designation, and incendiary purposes. Designed to be less intense than the M1 tracer, the M10 has an orange tip.
Cartridge, Caliber .50, Tracer, M17
Tracer for observing fire, signaling, target designation, and incendiary purposes. Can be fired from the M82/M107 series of rifles.
Cartridge, Caliber .50, Armor-Piercing-Incendiary-Tracer, M20
This cartridge is used, in place of the armor piercing round, against armored, flammable targets, with a tracer element for observation purposes. This cartridge is effectively a variant of the M8 Armor-Piercing Incendiary with the added tracer element. Can be fired from the M82/M107 series of rifles. This bullet has a red tip with a ring of aluminum paint.
Cartridge, Caliber .50, Tracer, Headlight, M21
Tracer for use in observing fire during air-to-air combat. Designed to be more visible, the M21 is 3 times more brilliant than the M1 tracer.
Cartridge, Caliber .50, Incendiary, M23
This cartridge is used against unarmored, flammable targets. The tip of the bullet is painted blue with a light blue ring.
Cartridge, Caliber .50, Ball, M33
This cartridge is used against personnel and unarmored targets. Can be fired from the M82/M107 series of rifles.
Cartridge, Caliber .50, Saboted Light Armor Penetrator, M903
This is a Saboted Light Armor Penetrator (SLAP) round, which uses a smaller 355-360 grain bullet fitted in an amber colored plastic sabot. For use only in the M2 series of machine guns.
Cartridge, Caliber .50, Saboted Light Armor Penetrator-Tracer, M962
Like the M903, this is a Saboted Light Armor Penetrator (SLAP) round, with the only difference being that the M962 also has a tracer element for observing fire, target designation, and incendiary purposes. It uses red colored plastic sabot for indentification. For use only in the M2 series of machine guns.
Cartridge, Caliber .50, Ball, XM1022
A long-range match cartridge specifically designed for long range work using the M107 rifle.
Cartridge, Caliber .50, M1022 Long Range Sniper
The .50 Caliber M1022 has an olive green bullet coating with no tip ID coloration. The projectile is of standard ball design. It is designed for long-range sniper training and tactical use against targets that do not require armor piercing or incendiary effect. It exhibits superior long range accuracy and is trajectory matched to MK211 grade A. The M1022 is ideal for use in all .50 Caliber bolt action and semi-automatic sniper platforms.
Cartridge, Caliber .50, Armor-Piercing-Incendiary, Mk 211 Mod 0
A so-called "combined effects" cartridge, the Mk 211 Mod 0 High-Explosive-Incendiary-Armor-Piercing (HEIAP) cartridge contains a .30 caliber tungsten penetrator, zirconium powder, and Composition A explosive. It can be used in any .50 caliber weapon in US inventory with the exception of the M85 machine gun. Cartridge is identified by a green tip with a grey ring.
Cartridge, Caliber .50, MK257 Armor Piercing Incendiary Dim Tracer
The .50 Caliber MK257 API-DT has a purple bullet tip. The bullet has a hardened steel core and incendiary tip. The .50 Caliber MK257 is used in machine guns M2, M3, and M85. Dim trace reduces the possibility of the weapon being located during night fire and is visible with night vision devices only.
Cartridge, Caliber .50, Armor-Piercing-Incendiary-Tracer, Mk 300 Mod 0
As with the Mk 211 Mod 0, but with a tracer component. This cartridge likely can be used in any .50 caliber weapon in US inventory with the exception of the M85 machine gun, as with the Mk 211 Mod 0. Cartridge is identified by an unknown coloring
Cartridge, Caliber .50, Armor-Piercing-Explosive-Incendiary, APEI-169, M02
This cartridge is used against hardened targets such as bunkers, for suppressive fire against lightly armored vehicles, and ground and aerial threat suppression. It is generally fired either from pilot-aimed aircraft-mounted guns or anti-aircraft platforms both produced by FN Herstal. It is identified by a gray over yellow tip. A tracer variant of it also exists.