The two most common assault rifles in the world are the Soviet AK-47 and the American M16. These Cold War-era rifles have been used in conflicts both large and small since the 1960s. They are used by military, police, security forces, revolutionaries, terrorists, criminals, and civilians alike and will most likely continue to be used for decades to come. As a result, they have been the subject of countless comparisons and endless debate.

The AK-47 was influenced by the design of the German StG 44. 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 were perfectly suited for the Soviet Army's new mobile warfare doctrines. More AK-type weapons have been produced than all other assault rifles combined. In 1974, the Soviets began replacing their AK-47 and AKM rifles with a newer design, the AK-74, which uses 5.45×39mm ammunition.

The M16 was adapted from the ArmaLite AR-15, and entered United States military service in the mid-1960s. Despite its early failures, the M16 proved to be a revolutionary design and stands as the longest-continuously serving rifle in American military history. The U.S. military has largely replaced the M16 in combat units with a shorter and lighter version called the M4 carbine.

History

Sturmgewehr 44

The Germans pioneered 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 overpowered for most small arms combat. They would soon develop a select-fire, intermediate-powered rifle, combining the firepower of a submachine gun with the range and accuracy of a rifle.

The result was the Sturmgewehr 44, which the Germans produced in large numbers; approximately half a million were made. It fired a new and revolutionary intermediate-powered cartridge, the 7.92×33mm Kurz. This new cartridge was developed by shortening the standard 7.92×57mm Mauser round and giving it a lighter 125-grain bullet that limited range but allowed for more controllable automatic fire. The smaller, lighter cartridge also allowed soldiers to carry more ammunition "to support the higher consumption rate of automatic fire."

The Sturmgewehr 44 features an inexpensive, easy-to-make, stamped steel design and a 30-round detachable box magazine. "This weapon was the prototype of all successful automatic rifles. Characteristically (and unlike previous rifles and the M14 rifle) it had a straight stock with the barrel under the gas cylinder to reduce the turning moment of recoil of the rifle in the shoulder and thus help reduce the tendency of shots to climb in automatic fire. The barrel and overall length were shorter than a traditional rifle and it had a pistol grip to hold the weapon more securely in automatic fire. The principle of this weapon — the reduction of muzzle impulse to get usable automatic fire within the actual ranges of combat — was probably the most important advance in small arms since the invention of smokeless powder."

AK-47

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. On July 15, 1943, a Sturmgewehr was demonstrated before the People's Commissariat of Arms of the USSR. The Soviets were so impressed with the Sturmgewehr, that they immediately set about developing an intermediate caliber automatic rifle of their own, to replace the PPSh-41 submachine guns and badly outdated Mosin–Nagant bolt-action rifles that armed most of the Soviet Army. The Soviets soon developed the 7.62×39mm M43 cartridge, the semi-automatic SKS carbine, and the RPD light machine gun. Shortly after World War II, the Soviets developed the AK-47 assault rifle, which would quickly replace the SKS in Soviet service. The AK-47 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 were perfectly suited for the Red Army's new mobile warfare doctrines. In the 1960s, the Soviets introduced the RPK light machine gun, itself an AK-47-type weapon with a bi-pod, a stronger receiver, and a longer, heavier barrel that would eventually replace the RPD light machine gun.

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). As a result, more AK-type weapons have been produced than all other assault rifles combined. "Of the estimated 500 million firearms worldwide, approximately 100 million belong to the Kalashnikov family, three-quarters of which are AK-47s."

M14 rifle On the other hand, 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 those of the Germans and Soviets, the U.S. Army failed to recognize the importance of the assault rifle concept, and instead maintained its traditional views and preference for high-powered semi-automatic rifles. At the time, the U.S. Army believed that the Sturmgewehr 44 was "intended in a general way to serve the same purpose as the U.S. carbine" and was in many ways inferior to the M1 carbine, and was of "little importance".

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. However, early experiments with select-fire versions of the M1 Garand proved disappointing. During the Korean War, the select-fire M2 Carbine largely replaced the submachine gun in US service and became the most widely used Carbine variant. However, 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 experienced major logistical problems during WWII and the Korean War–insisted that a single, powerful .30 caliber cartridge be developed, capable of being used by both the new automatic rifle and the new general-purpose machine gun (GPMG) in concurrent development.Fanaticism And Conflict In The Modern Age, by Matthew Hughes & Gaynor Johnson, Frank Cass & Co, 2005 This culminated in the development of the 7.62×51mm NATO cartridge.

The United States Army then began testing several rifles to replace the obsolete M1 Garand. Springfield Armory's T44E4 and heavier T44E5 were essentially updated versions of the Garand chambered for the new 7.62 mm round, while Fabrique Nationale submitted their FN FAL as the T48. ArmaLite entered the competition late, hurriedly submitting several AR-10 prototype rifles in the fall of 1956 to the United States Army's Springfield Armory for testing.Pikula, pp. 36, 38

The AR-10 featured an innovative straight-line barrel/stock design, forged aluminum alloy receivers, and phenolic composite stocks.Pikula, Major Sam. The ArmaLite AR-10. Regnum Fund Press, 1998. . pp. 27-29 It had rugged elevated sights, an oversized aluminumPikula, Sam (Major), The ArmaLite AR-10, p. 38: Later changed to titanium. flash suppressor and recoil compensator, and an adjustable gas system.Pikula, pp. 27-30 The final prototype featured an upper and lower receiver with the now-familiar hinge and takedown pins, and the charging handle was on top of the receiver placed inside of the carry handle. For a 7.62mm NATO rifle, the AR-10 was incredibly lightweight at only 6.85 lbs. empty. Initial comments by Springfield Armory test staff were favorable, and some testers commented that the AR-10 was the best lightweight automatic rifle ever tested by the Armory.Pikula, pp. 39-40

In the end, the United States Army chose the T44, now called the M14 rifle–an improved M1 Garand with a 20-round magazine and automatic fire capability. The U.S. also adopted the M60 general-purpose machine gun (GPMG). Its NATO partners adopted the FN FAL and HK G3 rifles, as well as the FN MAG and Rheinmetall MG3 GPMGs.

M16 rifle

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. And, while the M2 Carbine offered a high rate of fire, it was underpowered and ultimately outclassed by 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 over the speed of sound while matching or exceeding the wounding ability of the .30 Carbine cartridge.Hutton, Robert (ed.), The .223, Guns & Ammo Annual Edition, 1971.

This request ultimately resulted in the development of a scaled-down version of the Armalite AR-10, called the ArmaLite 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 the AR-10 to the rear of the receiver), the newly redesigned rifle was subsequently adopted as the M16 Rifle. "(The M16) was much lighter compared to the M14 it replaced, ultimately allowing soldiers to carry more ammunition. The air-cooled, gas-operated, magazine-fed assault rifle was made of steel, aluminum alloy, and composite plastics, truly cutting-edge for the time. Designed with full and semi-automatic capabilities, the weapon initially did not respond well to wet and dirty conditions, sometimes even jamming in combat. After a few minor modifications, the weapon gained in popularity among troops on the battlefield."

Despite its early failures, the M16 proved to be a revolutionary design and stands as the longest continuously serving rifle in American military history. It has been adopted by many U.S. allies and the 5.56×45mm NATO cartridge has become not only the NATO standard but "the standard assault rifle cartridge in much of the world." It also led to the development of small-caliber, high-velocity service rifles by every major army in the world, including the USSR and the People's Republic of China. It has been called a benchmark against which other assault rifles are judged.

Manufacturing philosophies

M16