KALASHNIKOV: The AK-47 & AKM Rifles, Part 2 of 2
By Frank Iannamico
Although AK-74s (most in their semiautomatic guise) and their 5.45x39mm ammunition are well known and common today, this was not always the case. At one time, the rifles were non-existent in the U.S. and the cartridges were high-end collector items.
The personnel at the U.S. Army Foreign Science and Technology Center had long heard references and reports regarding a Soviet infantry weapon called the AK-74. For a while, they thought that a careless typist had just transposed the AK-47 designation to read AK-74. During 1978, they received their first AK-74 rifle for test and evaluation. The very first feature to come to their attention was the AK-74’s large muzzle brake. After examining the AK-74’s 5.45x39mm cartridges, a few were disassembled and sectionalized. The bullet—with its hollow tip, steel core and lead envelope—piqued the interest of the evaluation team. During the same period, the Army was evaluating their new Kevlar helmets. To test the effectiveness of its diminutive cartridge, the AK-74 was fired at the helmet at a range of 100 meters. A small entry hole was made in the side of the helmet, and on the opposite side was blasted a 5-inch-wide hole.
The Russians initiated a program during 1976 to begin replacing all of their older AK and AKM 7.62x39mm weapons with the new 5.45x39mm AK-74 rifles. This move surprised many Western observers who had originally predicted that the issue of the small caliber AK-74 would be limited to select organizations like the Soviet Special Forces. The AK-74 received its initial baptism of fire during the 1979–1989 Soviet war in Afghanistan.
The AK-74 rifle is a high-velocity, 5.45x39mm (actual bullet diameter is 5.613mm/.221 caliber) version of the AKM rifle. The United States became the pioneer of the small caliber military service rifles when they adopted the M16 rifle in the mid-1960s during the Vietnam War. The Russians evidently became aware of the attributes of a small caliber weapon, as they began a program as early as 1964 to develop and eventually adopt a small caliber cartridge of their own. The advantages of a small caliber infantry weapon include the following: Both the weapon and ammunition are lighter in weight, allowing the individual soldier to carry a larger ammunition load, and the weapon is more accurate (controllable) in the full-automatic mode of fire. In the case of the AK-74, the rifle is considered to be more accurate because of the reduced recoil and the flatter trajectory of its bullet relative to the 7.62x39mm round. A high Soviet priority in the development of the AK-74 was reducing the overall weight of the weapon. The loaded weight of the AK-74 with laminated wood furniture is 8.4 pounds (3.81kg), and the overall length is 37 inches (940mm). Although aluminum (and later steel) magazines had been used on early prototypes, 30-round plastic magazines were adopted and issued with the weapons. Adopted along with the AK-74 rifle was a new system for the quick reloading of magazines, consisting of a stripper clip that could hold up to 15 rounds of ammunition and a stripper clip guide for loading the rounds into the magazine.
The small size of the 5.45x39mm cartridge case permitted significant improvements to the original bolt design. Due to the 5.45mm round’s small diameter base, a smaller bolt face could be implemented, which allowed the stem of the bolt to have a smaller diameter and a smaller corresponding hole in the bolt carrier to accommodate it. This provided an improved bolt carrier to bolt weight ratio of 6:1 over the 7.62x39mm AKM ratio of 5:1, resulting in a more reliable operation by providing the bolt additional forward inertia to chamber a recalcitrant cartridge. The improved weight ratio also increased the rearward velocity of the bolt, and thus a substantial increase in the extraction force. However, this also increased the stress exerted on the extractor claw, which increased its chances of failure. To solve the problem, the extractor was re-engineered to enable it to handle the increased force of the extraction. The 5.45mm cartridge case was designed with a thick 1.37mm rim to withstand both the increased rearward bolt velocity and extraction force.
Receiver
The receiver used in the manufacture of the AK-74 was basically the same stamped sheet metal design that was used for the AKM. One distinctive change was the addition of a dimple on the bottom of the receiver to accommodate the redesigned hammer-retarding mechanism. The hammer retarder and other fire control components featured a sleeve that allowed all the parts to be assembled outside of the receiver. The axis pin was installed through the center of the sleeve once the assembly was placed inside the receiver.
The selector positions were marked using the same Cyrillic characters as earlier models. However, the two elliptical depressions cut in the receiver for the selector lever were made slightly smaller. The mode of fire positions remained the same as for previous AK rifles: the top position was safe, the center position full-automatic and the lower position semiautomatic. There were other minor changes made to components like the trigger guards, and many of the internal parts, usually to simplify the manufacturing process, such as investment casting of parts like triggers, hammers, trip levers and others.
Gas Block
The original gas block on the early production AK-74 rifle was fitted with a gas port drilled at a 45-degree angle, like earlier 7.62x39mm AK and AKM rifles. This design resulted in bullet shear problems. It was discovered that the high-pressure gas generated from the high velocity 5.45x39mm cartridge, which was used to operate the weapon, was shearing metal from the bullets as they passed over the gas port. Soviet engineers solved the problem by designing the gas block with a port located at a 90-degree angle to the barrel. In addition, the gas port in the barrel was drilled into the barrel’s groove rather than the land. The 90-degree gas blocks are easily distinguished from earlier designs by their shape. The new gas blocks were implemented into production around 1977. Like the AKM model, the inside of the gas blocks were chromium-plated.
Bolt Carrier and Bolt
There were a few significant changes to the bolt and bolt carrier of the AK-74. The configuration of the cocking handle and other features were changed several times during production. The most significant change was to the gas piston, which was redesigned during 1989, eliminating the two circular grooves around the piston head and expediting the manufacturing process of the part. The bolt carrier continued to have black paint applied over a Parkerized base with a chromium-plated gas piston.
Buttstock and Handguards
The early production AK-74 laminated wood stocks and handguards were similar to those used on AKM rifles. Laminated wood provided the stock with exceptional strength and resistance to warping under the most extreme of conditions. During the mid-1980s, the traditional laminated AK wood was replaced by a PA 6 polymer buttstock and handguards that were “plum” in color. The plum-colored furniture was phased out by black polyamide plastic with the introduction of the AK-74M model around 1991.
Top Cover
As production continued, the strengthening ribs pressed into the top covers were not as pronounced, and a small indentation was added to the rolled edge at the ejection port area. Post-1993 production saw the return of the smooth top cover.
Selector Lever
The AK-74 selector lever was redesigned to fit under the top cover when placed in the safe position, rather than its upper edge running parallel with the edge of the top cover.
Barrel
Since the AK-74 barrel has a smaller diameter bore, it weighs slightly more than the barrel of a 7.62x39mm AKM, which has approximately the same outside diameter. The standard barrel length is 16.3 inches (415mm), with one right-hand turn in 7.85 inches (1:199mm), and both the chamber and bore are chromium plated. There are two mounting lugs present on the bottom of AK-74 barrels; the one in the rearmost position is an integral part of the gas block and is used to mount accessories, such as an underbarrel grenade launcher. The forward lug is for mounting a bayonet and is an integral part of the front sight base. The bayonet lug was moved forward from its former position on the gas block of the AKM model because of the AK-74 muzzle brake extending out the mount for the bayonet’s barrel ring. This allowed AKM bayonets to be used on AK-74 rifles. There are holes present in both lugs to allow the cleaning rod to pass. During AK production, the standard method of attaching the front sight base, gas block and rear sight base has always been with steel retaining pins. During the 1985–1986 period, a new method was developed, primarily to reduce production time. The new process uses a high-pressure punch press to peen the components in place, eliminating the drilling and pinning process. IZHMASH briefly returned to the pinning of the components on the 100 series of weapons.
Muzzle Brakes
One of the most interesting components to be introduced with the AK-74 is its unique—and effective—muzzle brake. There are several variants of the Russian muzzle brake; the primary differences lie in the size and shape of the collars, bridges and baffles, as well as the process of their manufacture. One feature of the AK-74 muzzle and muzzle devices that is different from earlier AK and AKM designs is the larger 24mm diameter of the threaded attachment point, which was manufactured as an integral part of the front sight assembly, and the use of right-hand threads in place of the former left-hand threads. The spring-loaded pin used to lock the muzzle devices in place was retained. Other countries that manufactured AK-74 designs in many cases reproduced exact or close copies of the muzzle brake, with slight variations, to one of the Russian designs. To resist the effects of firing corrosive ammunition, the inside surfaces of the muzzle brakes are usually chromium-plated.
AKS-74 Side-Folding Stock, 5.45x39mm
The AKS-74 rifle introduced a new, improved style of folding stock. The new stock folds to the left side, instead of under the receiver. With the stock extended, the shooter is provided with a much sturdier and more comfortable platform than the old under-folding stocks. A button is located on the left side of the receiver to release the stock to fold it. When folded, the spring-loaded button applies pressure to the stock to prevent it from rattling. To secure the stock when folded, a spring-loaded latch is incorporated on the left side of the receiver. The latch hooks onto a flange located on the left side of the buttplate.
AK-74M, 5.45x39mm
The AK-74M model was introduced during March of 1991; the letter M in the designation stands for “Modernized.” The AK-74M differs from the standard AK-74 in that it has a full-length, high-strength black polyamide plastic buttstock that is designed to fold to the left side of the receiver. This design permitted both the advantages of a rigid fixed stock and the compactness of a folding stock model.
The AKS-74U, 5.45x39mm
The AKS-74U, or Avtomat Kalashnikova Skladnoy Ukorochenniy model 1974, is a compact, short-barrel version of the 5.45x39mm AK-74 fitted with a side-folding metal skeleton buttstock. The Russians refer to the small AKS-74U as a “submachine gun,” although it would not be considered as such in the West because of its chambering for rifle ammunition.
Several countries manufacture variants of the 5.45x39mm AK-74. And, like for the previous AK designs, each country has small variances from the original design. As with other AK models, the Russian weapon is the benchmark that the others are compared to. Most countries adopting the AK-74 used the variant that was currently in Russian production as the basis for their model. Other countries that adopted the 5.45x39mm AK-74 pattern weapons include Bulgaria, East Germany, North Korea, Poland and Romania.
Although the Russians introduced and adopted the 5.45x39mm cartridge in 1974, it was not readily accepted by many of the Warsaw Pact nations then associated with the former Soviet Union. Many of the old 7.62x39mm AK and AKM pattern weapons were still quite serviceable. More importantly, however, most of the countries still had large stocks of 7.62x39mm ammunition. The popular 7.62x39mm could be found anywhere in the world and was a proven performer with very good penetration capabilities. Another setback to the 5.45x39mm round occurred when the Warsaw Pact began to disintegrate. Former members began applying for membership in NATO and ultimately adopted the 5.56x45mm cartridge.
Observations
After the Chinese and Egyptian semiautomatic AKs with stamped receivers were imported during the early 1980s, some were legally converted to select-fire in the relatively short window before the ban in 1986. After the AK-74 part kits and 5.45x39mm ammunition were imported, owners of converted AKs had their rifles upgraded to AK-74 specs.
The side-folding buttstocks on the AK-74 and AK-74M are a vast improvement over the under-folding versions of the AK and AKM. Furthermore, the 5.45x39mm AK-74 has mild recoil and is much easier to control in full-automatic than either the 7.62x39mm AK or AKM.
The AK-74’s reusable stripper clip system reduces the time to reload magazines to seconds. The content of the magazines has even continued to improve. WOLF and others offer commercial, non-corrosive 5.45mm ammo, with the predominantly corrosive surplus 5.45x39mm ammunition now banned.
RECOMMENDED READING
AK-47: The Grim Reaper II
Chipotle Publishing, LLC.
References:
Aberdeen Proving Ground, 11th Intelligence Bn, Technical Intelligence Bulletin TIB 2-25, “The AK-74 Assault Rifle.”
AKS-74 Assault Rifle Technical Data, CIS Translation, Chief Intelligence and Security NDHQ Ottawa, Canada, 1989.
Fackler, Martin L. M.D., Surinchak, John S. M.A., Malinowski, John A. B.S. and Bowen, Robert E., “Wounding Potential of the Russian AK-74 Assault Rifle,” Journal of Trauma, Vol. 24, No. 3, Williams & Wilkins Company, 1984.
Isby, David C., “Egyptian Infantry Weapons and Their Industrial Base,” Small Arms World Report, The Institute for Research on Small Arms in International Security, 1847 Vernon Street, NW, Washington, DC, Spring 1995.
Ranger, Mick, “Bulgarian Small Arms Manufacture, a Firsthand View,” Small Arms World Report, The Institute for Research on Small Arms in International Security, 1847 Vernon Street, NW, Washington, DC, February 1992.
Semenov, F., Engineer, “The AK-74M,” Small Arms World Report, The Institute for Research on Small Arms in International Security, 1847 Vernon Street, NW, Washington, DC, December 1992.
Small Arms Division, Royal Ordnance, Report No. RD/PR/49/86, “Evaluation of the Soviet 5.45mm RPK-74, 5.45mm AKS-74, 5.45mm AK SU and 7.62mm AK SU.”
Steadman, Nick, “East German Small Arms,” International Defense Review, November 1989.
Technical Intelligence Brief No. 2-25, “The AK-74 Assault Rifle, Aberdeen Proving Ground.”
LtCol Jonathan M. Weaver Jr. Infantry (Ret). Technical Report No.440, May 1987, “Army Materiel Command Systems Analysis. An Evaluation of the Soviet 5.45x39mm AK-74 and Type PS Ball Cartridge.”
Threat Division, Directorate of Intelligence and Security, US Army, Ft Benning, “The Soviet AK-74.”
This article first appeared in Small Arms Review V22N7 (August 2018) |
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