New Irons in the Army's Small Arms Fire
February 07, 2018
The article republished below, "New Irons in the Army's Small Arms Fire", shows the interest in maintaining firepower superiority after World War II and the Korean War led to advancements in manufacturing processes and the use of lightweight materials that changed small arms. "AR-10 automatic rifle. Army is very interested in this gun," Guns & Ammo reported in 1958. "Weighs only 7 pounds."
*Originally published in Guns & Ammo, Winter 1958, Volume 1, Issue 3
Since the end of World War II, a revolution has taken place in the United States Army. Today the results are apparent in every quarter of America's ''senior service." The venerable, three regiment, triangular division has been replaced by the pentomic division. The traditional regiment has given way to the hard-hitting battle group. My commanders move troops, equipment, and supplies by air. The howitzers and guns of the artillery have been supplemented, and may eventually be replaced, by rockets and atomic missiles. Radar is employed for battlefield surveillance and the detection and location of hostile mortars and fieldpieces. Field commanders view television screens to keep pace with a battle and ''fight'' their troops. Even more unique, the automatic foxhole digger is no longer a Cl's cynical joke but a reality. And nowhere are the results of this revolution in the Anny more apparent than in the field of small arms.
In 1960 an entirely new small aims weapon system will be introduced. The .45 caliber submachine gun, the·.30 caliber carbine, the M1 Garand and the Browning Automatic Rifle will be re placed by the M14 light rifle and the M15 heavy rifle. The two .30 caliber light machine guns and the water-cooled .30 caliber heavy will be replaced by the M60 general purpose machine gun. Thus five weapons, three new and two ''old-timers," the .45 pistol and the .50 caliber machine gun, will take the place of the present eight. Just as important, the familiar 30-06 Army ammunition will be replaced by the new 7.62-mm cartridge, which may sound a little ''foreign'' but is really as American as the Colt Peacemaker. All three of the new weapons, the M14 and M15 rifles and the M60 machine gun, and chambered for the 7.62-mm cartridge.
Now you might want to know what all this business about a revolution in the Army, the introduction of new military rifles, and the adoption of a new machine gun has to do with you, the average American shooter, hunter, or gun collector. The answer is everything!
First let's consider the possibility of another world conflict in which the United States is involved. Because the M1 Garand was available to the American infantrymen of World War II, he enjoyed a three to one superiority in fire power over his enemy counterpart. It's logical to assume that this superiority saved the life of many an American GI who found himself in a tight spot. The development and introduction of the semi-automatic/full-automatic M14 Army rifle guarantees the American soldier firepower superiority in the future; and who is the American soldier? You are, in time of war, you and your brothers and your sons. When you look at it in this light the fact that the Army is getting a new, easier loading, lighter weight, hard-hitting, reliable infantry rifle becomes personally important - it may someday save your life!
Furthermore, we can't afford to overlook the part that advances in military weapons design have played in the development and perfection of sporting arms. The actions of the two most popular sporting rifles in America, the bolt action Winchester Model ·70 and the Remington Model 721/722; are derivatives of the world famous Mauser military action. The Mannlicher-Schoenaver, undoubtedly one of the very finest sporting rifles available today, aside from a custom rifle, is the product of a man who devoted himself almost exclusively to the design of military weapons. Furthermore, the very desirable rotary or spiral box magazine that Ferdinand Ritter von Mannlicher devised f0r his Model 87-88 straight pull action Austrian military rifle is not only used in the Mannlicher-Schoenaver rifle but also in the very popular Savage Model 99. This rotary box magazine also promises to be the type magazine that will be modified to retain ''brass'' for subsequent reloading. And these are just a few examples of military developments that have been adapted to sporting rifles; to list them all would require a book.
Now this doesn't mean that the M14 and M15 military rifles will lead the way to the development, sale and general civilian use of high-powered, semi automatic sporting rifles, but it's a sure bet that the .308 Winchester cartridge, the commercial counterpart of the 7.62-mm cartridge which was a big develop ment item in the weapon system program, will become increasingly popular with the civilian shooter. Add to this the manufacturing techniques devised for the mass production of these purely military weapons and the characteristic extensive research in metallurgy and ballistics, the findings of which will be utilized by the American arms industry, and you have significant contributions to the development of more advanced sporting weapons.
As taxpayers, American shooters should also be gratified to learn that tax dollars spent on the Army's weapon system program have resulted in three of the finest military weapons of their type in the world today. Which leads to the questions: How were the new weapons developed? What exactly are they like?
In 1945/1946 the Army launched its program to develop a new infantry small arms weapon system with three major objectives in mind: 1) reduce the number of weapons; 2) standardize ammunition with America's western allies; and 3) reduce or lighten the infantryman's "load". If these objectives could be at tained then the problem of supply would be greatly reduced and the mobility of the infantryman greatly increased.
Although work began on the new, all purpose cartridge, the rifle and the new machine gun at approximately the same time, the 7.62-mm cartridge was adopted as standard prior to the adoption of the weapons. Had it not been for the objections of Great Britain the new cartridge could conceivably have been adopted by the NATO nations as early as 1947, but the British, who were promoting their own development, a .280 caliber (7-mm) cartridge, held out until December of 1953 when the U.S. Army's 7.62-mm (really a .30 caliber) was finally selected. Why was the adoption of our new cartridge so important to us? For two reasons: exterior ballistics of the 7.62-mm are approximately the same as 30-06 M2 ammunition, thus no sacrifice of stopping power or penetrating power was made as would have been the case if Britain's .280 had been chosen, and equally important, the new cartridge is appreciably lighter than M2 ammunition, 20 rounds of 7.62-mm weighing 1.04 pounds as compared with 1.18 pounds for 20 rounds of 30-06 M2. In this way then the problem of ammunition standardization was solved and the Army was well on its way to a sig nificant reduction of the infantryman's "load."
During the long period in which the new ammunition was being developed, tested, and considered, work was progressing steadily on a new infantry rifle. In accordance with the plans laid down in 1945, Army Ordnance had developed two light rifles the T44, in reality an extensive modification of the M1 and the T47 another gas-operated, semi-automatic/full-automatic light rifle. Meanwhile, in Belgium, Fabrique Nationale d'Armes de Guerre had developed the FN light military rifle, and in Britain a new .280 (7-mm) automatic rifle made its appearance. In 1950, a series of joint evaluation tests were conducted in the United States under the supervision of both English and American ordnance personnel. The results of these tests firmly decided the Americans against adoption of the .280 caliber and caused Army Ordnance to concentrate all future efforts on rifles chambered for the 7.62-mm cartridge (then known as the T65 cartridge). Eventually, after the firing of we'll over a million round of ammunition, the choice narrowed down to two rifles, the American T44 and the Belgian FN, or T48 as it was officially designated by the Army. After a great deal of discussion and further testing the T44 was finally selected as the Army's standard infantry rifle because it was light (about a pound), more suitable for mass production, and easier to train soldiers to use than the T48. Thus in 1957, after 12 years of effort, a new rifle was selected, to be placed in production in 1959 and issued to in 1960.
The new rifle, a product of the Springfield Arsenal's small arms designers, is a gas operated, semi-automatic/full-automatic shoulder weapon weighing 8¾ pounds and measuring 44.4 inches overall length with a 22-inch barrel. As noted previously it is an extensive modification of the M1 Garand, differing from the M1 in three respects. First, the new M14 is fed from a 20 round detachable magazine whereas the M1 has a self-contained, clip-fed magazine with a capacity of eight rounds. Second, the M14 is operated by a gas cutoff and expansion system, in which a measured amount of powder gas is tapped from the barrel and allowed to expand against a short piston to provide the force to operate the action, whereas the M1 is operated by an impingement-type gas system in which powder gases tapped from the barrel are channeled directly to the piston face, the sharp blow on the piston causing the action to function. Third, the M14 may be fired full automatic by rotating a selector, located at the rear right of the receiver, until the letter ''A'' faces the firer, this actuates a sear-release device which prevents the sear from restraining the hammer after a new cartridge has been seated - the M1, of course, can only be fired semi automatically.
With the exception of a ¼-inch extension on the sear, which contacts the sear release assembly, the trigger group of the M14 is identical to that used in the M1. The receiver, shortened to facilitate use of the 7.62-mm cartridge which is approximately a ½ inch shorter than the 30-06 M2 cartridge, is also identical to the M1 receiver. The rear-sight assembly is exactly the same for both rifles and the bolt is practically identical. The M14 operating rod, although of the same general shape as the M1's, is appreciably shorter. The M14 quite naturally has a bayonet lug, and provisions have been made for the attachment of a grenade launcher to the flash suppressor, the slotted cylinder just forward to the front sight.
The firing cycle of the M14 is also quite similar to that of the M1. When a round is fired the powder gases are tapped from the barrel and in turn pass into the gas cutoff and expansion system. A measured quantity of powder gas expands and exerts force on the face of the short piston which is the forward part of the operating rod. As the operating rod is forced back a coil spring contained in the rod is compressed over a spring guide. After approximately a ½ inch of free movement a camming surface on the inside of the operating-rod handle at the extreme rear of the rod contacts a bolt lug, causing the bolt to rotate counterclockwise, unlock and move to the rear with the operating rod. The bolt moving to the rear, extracts and ejects the empty shell and cocks the hammer. Rearward movement stops when the bolt contacts the rear of the receiver. At this point the compressed operating-rod spring starts to expand, causing the operating rod and the bolt to begin moving forward. A round is stripped from the top of the magazine and pushed into the chamber ahead of the bolt. As the bolt moves forward it rides over the compressed hammer which tends to rise, however, it is caught and held by the sear engaging the rear hammer hook. When the trigger finger is relaxed the sear releases the hammer which is then restrained by the trigger lug which engages the forward hook of the hammer. Nearing the limit of forward movement, the camming surface on the inside of the operating-rod handle causes the bolt to now rotate clock wise and lock. To begin the firing cycle again the trigger is pressed, the forward hammer hook is freed from the trigger lug, the hammer rotates upward and strikes the firing pin.
The foregoing description applies to M14 semi-automatic fire. When operated on full-automatic, the operating rod moving forward actuates a connector which causes a sear release to operate. The sear release disengages the sear from the rear hammer hook and as long as the trigger is depressed, the hammer is free to rotate upward and strike the firing pin. Thus the rifle's action will continue cycling until the magazine is empty.
The M15 (known as the T44E1 during development) is the companion piece to the M14. It is also a semi-automatic/full-automatic rifle with ap proximately the same linear dimensions as the M14, however, it is fitted with a heavy barrel, bipod rest and butt strap; it weighs 13.7 pounds, roughly 7 pounds less than the Browning Automatic. Since it was designed to be used primarily as an automatic rifle it differs from the M14 in that it is equipped with a rate reducer which results in a slow lock time and reduces the rate of automatic fire; aside from this the actions of the rifles are identical. This similarity has one outstanding benefit; once a man has been trained in the operation and maintenance of the M14, it will only require a few hours additional training to convert him into an automatic rifleman using the M15. In effect then, the Army's new 11 man squad will contain two full-time automatic riflemen and eight potential replacements!
Now that the Army has achieved so much, will infantry rifle development stop here? Will the Army be satisfied with its two new rifles and discontinue all research in this area? The answer is an emphatic no. In fact Army Ordnance is presently very much interested in Fairchild Aircraft's AR-10 automatic rifle. This radical new weapon can fire full-automatic or semi-automatic, utilizing a 20-round magazine. Employing a steel barrel, aluminum and stainless steel action and fiberglass and plastic foam stocks, the AR-10 has still other features differentiating it from any other rifle. It weighs seven pounds - pounds less than the M14 and the Belgian FN T-48. It is almost three pounds lighter than the 9½ pound Garand and is approximately the same weight as the M2 carbine. The AR-10 has a variable rate of fire; the present weapons firing about 600 rounds per minute.
The AR-10 differs from the usual gas operated weapon in that it does not use the normal piston and operating rod type action. Gas is channeled from a point near the muzzle through a tube feeding and operating a multiple-lug rotating bolt and carrier assembly. The 20-round non-ferrous alloy magazine itself represents a distinct advance in lightweight design, since it weighs less than four ounces and permits a rifleman to carry a 100-round supply all in pre-loaded magazines. Present steel magazines weigh twice as much. The muzzle brake and Hash suppressor of the AR-10 are of new design and help make handling of the rifle under automatic fire a comparatively easy matter, giving greater stability with consequent improvement in accuracy of fire under field conditions. The AR-10 has been provided with a built-in carrying handle, large enough for Arctic mittens, situated. at the balance point, above and integral with the receiver. This handle also houses and protects the rear aperture sight and its simplified elevation adjustment. A simple protective dust cover is provided and a winter trigger is incorporated in the design. Because of the materials used, the AR-10 is highly corrosion-resistant, lending itself to lowered maintenance, longer useful life, in expensive storage and immediate avail ability for use after storage.
The basic AR-10 weapon, with minor changes now being developed, will do the job of 1) a light machine gun, 2) a heavy machine gun, 3) a carbine, and of course, an infantry. This is truly a weapon of the future, not only militarily speaking but also from the standpoint of the civilian shooter. Such innovations as the barrel liner and the reduction of weight by the use of aluminum in the action and the replacement of the wooden stock with one of a light weight plastic material, herald the coming of a true lightweight ''sporter." Something American shooters have been dreaming about for years.
Something they haven't been dreaming about for years, or let's hope they haven't, is the third member of the Army's new weapon system the M60 general purpose machine gun. Developed during the same period that witnessed the evolution of the M14 and M15 rifles the M60 represents the combined efforts of U.S. Army Ordnance, the Bridge Tool & Die Works and the Inland Manufacturing Division of General Motors.
The new machine gun is equipped with a bipod, carrying handle, shoulder stock, and special ammunition belt container, clipped to the left side of the receiver, for use as an assault weapon. When used to provide supporting fire, and for sustained fire in a defensive position, the M60 is mounted on a light-weight, aluminum tripod, fitted with springs to absorb recoil - when so used the gun is belt-fed from separate, conventional ammunition boxes or cans.
The barrel, front sight, flash suppressor, gas system and bipod make up one assembly; when the barrel is changed a whole new assembly is installed. The perforated sheet metal ''skirts'' that form an integral part of each bipod leg, not only stiffen the legs but when folded also provide a heat shield and hand hold that facilitates changing hot barrels.
Externally the M60 has the same general appearance as the World War II German MG42 - the weapon that inspired its development. However, the similarity, caused by the extensive use of formed sheet metal parts on both guns, is really only ''skin deep," for the MG42 was recoil-operated, the M60 is gas-operated (gas cutoff and expansion system).
The M60 employs a rotary locking type bolt in conjunction with the gas system, and is unique in that headspace is fixed, permitting quick barrel changes; as with most light machine guns it's air-cooled.
And there we have it, the completely new Army small arms weapon system. Conceived at a time when the phrase "weapon system" and the concept it represents were virtually unknown to the other services who have recently gotten so much "mileage" out of publicizing this approach to arms development. Although it has been mentioned previously it's worth noting again that the adoption of this new weapon system in 1960 will provide the American soldier with vastly superior firepower, and, because of the emphasis on weight reduction that characterized the program, give him the mobility he will desperately need if he is to survive in a war in which tactical nuclear weapons are employed.