. 50 BMG The . 50 Browning Machine Gun ( . 50 BMG ) or 12 . 7×99mm NATO 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 . Under STANAG 4383 , it is a standard cartridge for NATO forces as well as many non - NATO countries . The cartridge itself has been made in many variants : multiple generations of regular ball , tracer , armor piercing , incendiary , and sabot ed sub - caliber round s . The rounds intended for machine guns are linked using metallic links . The . 50 BMG cartridge is also used in long - range target and sniper rifle s , as well as other . 50 caliber machine guns . The use in single - shot and semi - automatic rifles has resulted in many specialized match - grade rounds not used in . 50 caliber machine guns . A McMillan Tac - 50 . 50 BMG sniper rifle was used by Canadian Army Corporal Rob Furlong of the PPCLI to achieve what was then the longest - range confirmed sniper kill in history , when he shot a Taliban combatant at 2 , 430 meters ( 2 , 657 yards ) during the 2002 campaign in the Afghanistan War . This record was surpassed in 2009 in Afghanistan by a British sniper , though using a . 338 Lapua Magnum ( 8 . 58×70 mm ) rifle . A former record for a confirmed long - distance kill was set by U . S . Marine sniper Carlos Hathcock in 1967 , at a distance of ; Hathcock used the . 50 BMG 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 specifically for this round . DARPA ( Defense Advanced Research Projects Agency ) has contracted with Lockheed Martin to develop the EXACTO program , including . 50 - caliber bullets complete with microprocessors and steering vanes that allow the bullet to adjust its trajectory mid - flight to stay on target when the flight path has been altered by uncontrollable variables , as well as weapons that fire these rounds and monitor their flight . The weapon system is expected to be available in 2015 . 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 . History . John Browning had the idea for this round during World War I in response to a need for an anti - aircraft weapon , based on a scaled - up . 30 - 06 Springfield design , used in a machine gun 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 ) . 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 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 WWI ; however , the development of the U . S . . 50 caliber 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 ; 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 caliber armor - piercing cartridges went 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 was chambered in high - powered rifles as well . The concept of a . 50 caliber 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 rapid fire guns such as the original Gatling . During World War II the . 50 BMG was primarily used in the M2 Browning machine gun for anti - aircraft purposes . An upgraded variant of the M2 Browning 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 , thus making it a much less flexible weapon . It still has more penetrating power than lighter weapons such as general - purpose machine gun s , though it is significantly heavier and more cumbersome to transport . Its range and accuracy , however , are superior to light machine gun s 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 . 7mm DShK , NSV , which are ballistically very similar to the . 50 BMG , but 14 . 5 mm KPV machine guns have significantly superior armor 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 . Power . 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 both World Wars and a popular caliber amongst American hunters , can produce muzzle energies between 2 , 000 and 3 , 000 foot - pounds of energy ( between 3 and 4 kilojoules ) . The . 50 BMG round can produce between 10 , 000 and 15 , 000 foot pounds ( between 14 and 18 kilojoules ) , 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 . Cartridge dimensions . The 50 BMG 12 . 7 × 99 NATO cartridge has a capacity of 290 grains HO ( 19 ml ) . 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 . Average chamber pressure in for this round as listed in TM43 - 0001 - 27 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 ) . Military cartridge types . " . 50 BMG cartridges are also produced commercially with a plethora of different bullets and to a number of different specifications . " Links used for feeding machine guns . Two distinct and non - compatible metallic links have been used for the . 50 BMG cartridge , depending upon the machine gun which will be firing the cartridges . The M2 and M9 links , " pull - out " designs , are used in the Browning M2 and M3 machine guns . Pull - out cloth belts were also used at one time , but have been obsolete since 1945 . The M15 - series " push - through " links were used in the M85 machine gun . When the M85 was taken out of service , large stocks of ammunition linked with the M15 link remained in US military storage because of the ease with which linked ammunition can be de - linked and re - linked with different ( i . e . in service ) links . Legal issues . The specified maximum diameter of an unfired . 50 BMG bullet is ; while this appears to be over the . 50 inch ( 12 . 7 mm ) maximum allowed for non - sporting Title In small arms 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 , a mechanism which in firearms terms is known as engraving . 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 , smaller caliber rifles produce better scores and tighter groups in competitions . In response to legal action against the . 50 BMG in the United States and Europe , an alternative chambering was developed . The . 510 DTC Europ uses the same bullet , but has slightly different case dimensions . . 510 DTC cases can be made by fire - forming . 50 BMG cases in a . 510 DTC chambered rifle . The new round has almost identical ballistics , but because of the different dimensions , rifles chambered for . 50 BMG cannot fire the . 510 DTC , and therefore rifles chambered for . 510 DTC do not fall under many of the same legal prohibitions . Barrett offers a similar alternative , the . 416 Barrett , which is based on a shortened . 50 BMG case necked down to . 416 caliber ( 10 . 3 mm ) . 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 . Most of the instances of criminal activity cited in the Office of Special Investigations briefing involved the illegal possession of a . 50 BMG rifle . The briefing did not identify any instance of a . 50 BMG rifle being used in the commission of a murder . Within the United Kingdom , it is legal to own a . 50 BMG rifle with a section 1 Firearms Certificate . Typical uses . The primary military use of this round is in the Browning M2HB heavy machine gun . The primary civilian users of . 50 caliber rifles , which range in price from around US $ 1 , 600 for single shot AR - 15 upper conversions to well over US $ 8 , 000 for the semi - automatic , magazine - fed Barrett M82A1 , are long - range target shooters ; the Fifty Caliber Shooters Association , for instance , holds . 50 BMG shooting matches nationwide in the U . S . The U . S . Coast Guard uses . 50 BMG rifles to disable outboard engines from armed helicopters 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 . If it is necessary to breach barriers , a . 50 BMG round will penetrate most commercial brick walls and concrete cinder blocks . In addition to long - range and anti - materiel sniping , the U . S . military uses . 50 BMG weapons to detonate unexploded ordnance from a safe distance . The Raufoss Multipurpose round has sufficient terminal performance to disable most unarmored and lightly armored vehicles , making . 50 BMG caliber weapons helpful in anti - insurgency operations . The cartridge is also used by some hunters for taking game at extreme ranges ; while the energy of the . 50 BMG at close range is excessive for most game , at long ranges the velocity has dropped to levels that allow the taking of game animals without excessive damage to the animal .