Automatic rifle An automatic rifle is a type of magazine - fed rifle that uses either its recoil or a portion of the gas propelling the projectile to remove the spent cartridge case , cock the rifle , load a new cartridge and fire again repeatedly , as long as the trigger is held down or until the magazine is exhausted . Automatic rifles are distinguished from semi - automatic rifles in their ability to fire more than one shot in succession once the trigger is pulled . Most automatic rifles are select - fire weapons which are capable of firing in both full - automatic and semi - automatic . History . The world ' s first automatic rifle was the Mondragón rifle designed by Mexican General Manuel Mondragón , but manufactured in Switzerland by SIG . Mondragón began work in 1882 and patented the weapon in 1887 . It was created with the intention of giving a single infantry man the fire power of an entire squad and was subsequently adopted by the Mexican army . It saw combat during the Mexican Revolution , with about 400 guns having been delivered before a blockade interfered . SIG surplus Mondragóns ( around 1000 ) made their way to World War I , where the gun was mostly carried by German air crews of the Luftstreitkräfte under the designation FSK15 . It suffered from poor reliability and most were withdrawn from service before the war ended . The British experimented with the automatic Farquhar - Hill rifle before and during World War I , but it was quickly abandoned . The Italian Cei - Rigotti did not fare any better . The Browning Automatic Rifle ( BAR ) made its successful combat debut in World War I . The BAR arose from the concept of " Walking Fire " , an idea urged upon the Americans by the French who used the Chauchat light machine gun to fulfill that role . The BAR never entirely lived up to the desigers hopes ; being neither a rifle nor a machinegun . However , for its day it was a brilliant design and was the standard squad automatic rifle for the U . S . Military throughout World War II and the Korean War . Another automatic rifle that made its debut during World War I was the Russian Fedorov Avtomat , chambered in 6 . 5×50mmSR Arisaka . Initially it was an emergency conversion of semi - automatic rifles designed by Fedorov . Approximately two dozen Fedorov Avtomats saw combat in during World War I . A factory in Kovrov produced this gun in about 3000 exemplars mainly after 1920 . The Fedorov Avtomat saw more significant use during the Russian Civil War , particularly in the hands of the Red Finns during the Karelian Uprising . Because they depended on foreign ammunition , the Fedorov Avtomats were withdrawn from service by 1928 and stockpiled . Officially they were replaced in Soviet service with new submachine guns , like the PPD , and by 7 . 62 mm automatic rifles , like the AVS - 36 . But poor production and bureaucratic bungles ensured that by the start of the Winter War ( 1939 ) , very few substitutes had been produced . So the Fedorov Avtomats were rushed back in service against the Finns . The Germans were the first to pioneer the assault rifle concept , during World War II , based upon research that showed that most firefights happen within 400 meters and that contemporary rifles were over - powered for most small arms combat . The Germans sought to develop a select - fire intermediate powered rifle combining the firepower of a submachine gun with the accuracy and range of a rifle . This was done by shortening the standard 7 . 92x57mm cartridge to 7 . 92x33mm and giving it a lighter 125 grain bullet , that limited range but allowed for more controllable automatic fire . The result was the Sturmgewehr 44 . Like the Germans , the Soviets were influenced by experience showing most combat happens within 400 meters and that their soldiers were consistently outgunned by heavily armed German troops , especially those armed with the Sturmgewehr 44 assault rifles . The Soviets were so impressed with the Sturmgewehr 44 , that after World War II , they held a design competition to develop an assault rifle of their own . The winner was the AK - 47 . It was finalized , adopted and entered widespread service in the Soviet army in the early 1950s . Its firepower , ease of use , low production costs , and reliability was perfectly suited for the Red Army ' s new mobile warfare doctrines . The AK - 47 was widely supplied or sold to nations allied with the USSR and the blueprints were shared with several friendly nations ( the People ' s Republic of China standing out among these with the Type 56 ) . The U . S . Army was influenced by combat experience with semi - automatic weapons such as the M1 Garand and M1 carbine , which enjoyed a significant advantage over enemies armed primarily with bolt - action rifles . Although U . S . Army studies of World War II combat accounts had very similar results to that of the Germans and Soviets , the U . S . Army maintained its traditional views and preference for high - powered semi - automatic rifles . After World War II , the United States military started looking for a single automatic rifle to replace the M1 Garand , M1 / M2 Carbines , M1918 Browning Automatic Rifle , M3 " Grease Gun " and Thompson submachine gun . In the Korean War , the select - fire M2 Carbine largely replaced submachine gun s in US service . However , early experiments with select - fire versions of the M1 Garand proved disappointing . Also , combat experience suggested that the . 30 Carbine round was underpowered . American weapons designers reached the same conclusion as the Germans and Soviets : an intermediate round was necessary , and recommended a small caliber , high velocity cartridge . However , senior American commanders having faced fanatical enemies and experienced major logistical problems during WWII and the Korean War , insisted that a single powerful . 30 caliber cartridge be developed , that could not only be used by the new automatic rifle , but by the new general purpose machine gun ( GPMG ) in concurrent development . This culminated in the development of the 7 . 62x51 NATO cartridge and the M14 rifle which was basically an improved select - fire M1 Garand with a 20 round magazine . The U . S . also adopted the M60 GPMG . Its NATO partners adopted the FN FAL and HK G3 rifles , as well as the FN MAG and Rheinmetall MG3 GPMGs . The first confrontations between the AK - 47 and the M14 came in the early part of the Vietnam War . Battlefield reports indicated that the M14 was uncontrollable in full - auto and that soldiers could not carry enough ammo to maintain fire superiority over the AK - 47 . A replacement was needed : A medium between the traditional preference for high - powered rifles such as the M14 , and the lightweight firepower of the M2 Carbine . As a result , the Army was forced to reconsider a 1957 request by General Willard G . Wyman , commander of the U . S . Continental Army Command ( CONARC ) to develop a . 223 caliber ( 5 . 56 mm ) select - fire rifle weighing 6 lbs ( 2 . 7 kg ) when loaded with a 20 round magazine . The 5 . 56mm round had to penetrate a standard U . S . helmet at 500 yards ( 460 meters ) and retain a velocity in excess of the speed of sound , while matching or exceeding the wounding ability of the . 30 Carbine cartridge . This request ultimately resulted in the development of a scaled - down version of the Armalite AR - 10 , called AR - 15 rifle . However , despite overwhelming evidence that the AR - 15 could bring more firepower to bear than the M14 , the Army opposed the adoption of the new rifle . In January 1963 , Secretary of Defense Robert McNamara concluded that the AR - 15 was the superior weapon system and ordered a halt to M14 production . At the time , the AR - 15 was the only rifle available that could fulfill the requirement of a universal infantry weapon for issue to all services . After modifications ( Most notably : the charging handle was re - located from under the carrying handle like AR - 10 to the rear of the receiver ) , the new redesigned rifle was subsequently adopted as the M16 . In March 1970 , the U . S . recommended that all NATO forces adopt the 5 . 56x45mm cartridge . This shift represented a change in the philosophy of the military ' s long - held position about caliber size . By the middle of the 1970s , other armies were looking at M16 - style weapons . A NATO standardization effort soon started and tests of various rounds were carried out starting in 1977 . The U . S . offered the 5 . 56x45mm M193 round , but there were concerns about its penetration in the face of the wider introduction of body armor . In the end the Belgian 5 . 56x45mm SS109 round was chosen ( STANAG 4172 ) in October 1980 . The SS109 round was based on the U . S . cartridge but included a new stronger , heavier , 62 grain bullet design , with better long range performance and improved penetration ( specifically , to consistently penetrate the side of a steel helmet at 600 meters ) . During the 1970s , the USSR developed the AK - 74 and the 5 . 45x39mm cartridge , which has similar physical characteristics to the U . S . 5 . 56x45mm cartridge . Also during the 1970s , Finland , Israel , South Africa and Sweden introduced AK type rifles in 5 . 56x45mm . During the 1990s , the Russians developed the AK - 101 in 5 . 56x45mm NATO for the world export market . In addition , Bulgaria , Czechoslovakia , Hungary , Poland and Yugoslavia ( i . e . , Serbia ) have also rechambered their locally produced AK variants to 5 . 56mm NATO . The adoption these rifles cemented the world - wide trend toward small caliber , high velocity cartridges . In 1977 , Austria introduced the 5 . 56x45mm Steyr AUG bullpup rifle , often cited as the first successful bullpup rifle , finding service with the armed forces of over twenty countries . It was highly advanced for the 1970s , combining in the same weapon the bullpup configuration , a polymer housing , dual vertical grips , an optical sight as standard , and a modular design . Highly reliable , light , and accurate , the Steyr AUG showed clearly the potential of the bullpup layout . In 1978 , France introduced the 5 . 56x45mm FAMAS bullpup rifle . And in 1985 , the British introduced the 5 . 56x45mm L85 bullpup rifle . The adoption these rifles emphasized the trend from traditional designs to bullpup designs . Having learned from extensive combat experience , Israel Military Industries began to develop a bullpup rifle in the early 1990s . The result was the Tavor TAR - 21 which is an extremely light , accurate , reliable and fully ambidextrous bullpup rifle . The Tavor has been adopted by other countries ( most notably India ) . The Tavor was closely followed by Singapore ' s SAR 21 , the South African Vektor CR - 21 and the Iranian army ' s KH - 2002 . Also , China ' s People ' s Liberation Army ' s ( the worlds largest army ) adopted QBZ - 95 . By the turn of the century , the bullpup design had achieved world - wide acceptance .