AKM

The AKM is a 7.62×39 mm Soviet assault rifle introduced in 1959 as a lighter, more modern successor to the AK-47.
Designed by Mikhail Kalashnikov, it became the most widely produced variant of the Kalashnikov series, serving as the standard service rifle of the Soviet Army and Warsaw Pact states. Featuring a gas‑operated rotating bolt, slanted muzzle compensator, and simplified manufacturing for cost‑effective mass production, the AKM enhanced automatic accuracy and reliability while reducing weight by approximately 1 kg.
Though replaced in Soviet frontline units by the AK‑74 in the 1970s, variants of the AKM continue to be manufactured and remain in use today.

Design details

The AKM is an automatic rifle chambered in 7.62×39mm intermediate cartridge. It is a selective fire, gas operated with a rotating bolt, firing in either semi-automatic or fully automatic, and has a cyclic rate of fire of around 600 rounds per minute. The gas operated action has a large bolt carrier with a permanently attached long stroke gas piston. The gas chamber is located above the barrel. The bolt carrier rides on the two rails, formed on the side of the receiver, with a significant space between the moving and stationary parts.

Improvements over AK-47

Compared with the AK-47, the AKM features detailed improvements and enhancements that optimized the rifle for mass production; some parts and assemblies were conceived using simplified manufacturing methods. Notably, the AK-47's milled steel receiver was replaced by a U-shaped steel stamping. As a result of these modifications, the AKM's weight was reduced by ≈, the accuracy during automatic fire was increased and several reliability issues were addressed. The AK-47's chrome-lined barrel was retained, a common feature of Soviet weapons which resists wear and corrosion, particularly under harsh field conditions and near-universal Eastern Bloc use of corrosively primed ammunition.
The AKM's receiver is stamped from a smooth sheet of steel, compared with the AK-47 where the receiver was machined from a solid block of steel. A rear stock trunnion and forward barrel trunnion are fastened to the U-shaped receiver using rivets. The receiver housing also features a rigid tubular cross-section support that adds structural strength. Guide rails that assist the bolt carrier's movement which also incorporates the ejector are installed inside the receiver through spot welding. As a weight-saving measure, the stamped receiver cover is of thinner gauge metal than that of the AK-47. In order to maintain strength and durability it employs both longitudinal and latitudinal reinforcing ribs.

Barrel

The AKM has a barrel with a chrome-lined bore and four right-hand grooves at a 240mm or 31.5 calibers rifling twist rate. The forward barrel trunnion has a non-threaded socket for the barrel and a transverse hole for a pin that secures the barrel in place. The AKM's barrel is installed in the forward trunnion and pinned. Additionally the barrel has horizontal guide slots that help align and secure the handguards in place. To increase the weapon's accuracy during automatic fire, the AKM was fitted with a slant cut compensator that helps redirect expanding propellant gases upward and to the right during firing, which mitigates the rise of the muzzle during an automatic burst when held by a right-handed firer. The compensator is threaded on to the end of the barrel with a left-hand thread. Not all AKMs have slant compensators; some were also fitted with the older muzzle nut which came from the AK-47. Most AKMs with muzzle nuts were older production models. The AKM's slant compensator can also be used on the AK-47, which had a simple nut to cover the threads.

Gas block

The gas block in the AKM does not have a cleaning rod capture or sling loop but is instead fitted with an integrated bayonet support collar that has a cleaning rod guide hole. The forward sling loop was relocated to the front handguard retainer cap. The handguard retainer also has notches that determine the position of the handguards on the barrel. The AKM's laminated wood handguards have lateral grooves that help securely grip the rifle.
Gas relief ports that alleviate gas pressure in the piston cylinder were moved forward to the gas block and placed in a radial arrangement.

Bolt carrier assembly

The AKM's bolt carrier has a lightening cut milled into the right side halfway before the handle. The handle has its profile slimmed down as well. The stem of the AKM bolt is fluted in another measure to help reduce weight. The round, fluted firing pin of the AK-47 was also replaced with a flat one on the AKM. All pieces are typically painted black instead of left unfinished.

Stock

The buttstock, lower handguard and upper headguard are manufactured from birch plywood laminates like the later model AK-47 furniture. Such engineered woods are stronger and resist warping better than the conventional one-piece patterns, do not require lengthy maturing, and are cheaper.
The wooden buttstock used in the AKM is further hollowed in order to reduce weight and is longer and straighter than that of the AK-47, which assists accuracy for subsequent shots during rapid and automatic fire. The wooden stock also houses the issued cleaning kit, which is a small diameter metal tube with a twist lock cap. The kit normally contains the cleaning jag to which a piece of cloth material is wrapped around and dipped into cleaning solution. It also contains a pin punch, an assembly pin to hold the trigger, disconnector and rate reducer together while putting these back into the receiver after cleaning the weapon, and a barrel brush. The kit is secured inside the butt stock via a spring-loaded trapdoor in the stock's pressed sheet metal butt cap. The stock is socketed into a stepped shaped rear trunnion with single upper tang and two screws. The rear trunnion itself is held to the stamped receiver with four rivets. Under folding models instead have a U-shaped rear trunnion that reinforces the locking arms and is held to the receiver with six rivets.

Recoil/return spring assembly

The AKM uses a modified recoil/return spring mechanism, which replaces the telescoping recoil spring guide rod with a dual U-shaped wire guide.

Trigger assembly

The AKM has a modified trigger assembly, equipped with a hammer-release delaying device commonly called a "rate reducer" or "hammer retarder". In fact its primary purpose is not to reduce the rate of automatic fire; it is a safety device to ensure the weapon will only fire on automatic when the bolt is fully locked, as the hammer is tripped by the bolt carrier's last few millimeters of forward movement. The device also reduces "trigger slap" or "trigger bounce" and the weapon's rate of fire, which also reduces the dispersion of bullets when firing in fully automatic mode. The hammer was also changed and equipped with a protrusion that engages the rate reducer and the trigger has only one notched hammer release arm.

Sights

The AKM's notched rear tangent iron sight is calibrated in increments from and compared with the AK-47 the leaf's position teeth that secure the sliding adjustable notch were transferred over from the right to the left edge of the ramp.
The front sight is a post adjustable for elevation in the field and has a slightly different shape with the "ears" being angled with the back of the base instead of straight and its bottom portion is more narrow compared with the AK-47. Horizontal adjustment requires a special drift tool and is done by the armoury before issue or if the need arises by an armourer after issue. The sight line elements are approximately over the bore axis. The "point-blank range" battle zero setting "П" on the 7.62×39mm AKM rear tangent sight element corresponds to a zero. For the AKM combined with service cartridges the 300 m battle zero setting limits the apparent "bullet rise" within approximately relative to the line of sight. Soldiers are instructed to fire at any target within this range by simply placing the sights on the center of mass of the enemy target. Any errors in range estimation are tactically irrelevant, as a well-aimed shot will hit the torso of the enemy soldier.

Ammunition

The weapon uses the same ammunition as the AK-47: the 7.62×39mm M43 intermediate rifle cartridge.
The AKM mechanism's design principles and procedures for loading and firing are practically identical to those of the AK-47, the only difference being the trigger assembly as a result of incorporating the rate reducer device.

Magazines

The early slab-sided steel AK-47 30-round detachable box magazines had sheet-metal bodies and weigh empty. The later steel AKM 30-round magazines had lighter sheet-metal bodies with prominent reinforcing ribs weighing empty. To further reduce weight a light weight magazine with an aluminium body with a prominent reinforcing waffle rib pattern weighing empty was developed for the AKM that proved to be too fragile and the small issued amount of these magazines were quickly withdrawn from service. As a replacement steel-reinforced 30-round plastic 7.62×39mm box magazines were introduced. These magazines discolour over time from yellowish to rust-coloured shades, weigh empty and are often mistakenly identified as being made of Bakelite, but were actually fabricated from two-parts of AG-4S moulding compound, assembled using an epoxy resin adhesive. Noted for their durability, these magazines did, however, compromise the rifle's camouflage and lacked the small horizontal reinforcing ribs running down both sides of the magazine body near the front that were added on all later plastic magazine generations. A second generation steel-reinforced dark-brown 30-round 7.62×39mm magazine was introduced in the early 1980s, fabricated from ABS plastic. The third generation steel-reinforced 30-round 7.62×39mm magazine is similar to the second generation, but is darker coloured and has a matte non-reflective surface finish. The current issue steel-reinforced matte true black non-reflective surface finished 7.62×39mm 30-round magazines, fabricated from ABS plastic weigh empty.
Early steel AK-47 magazines are long, and the later ribbed steel AKM and newer plastic 7.62×39mm magazines are about shorter.
The transition from steel to mainly plastic magazines yielded a significant weight reduction and allow a soldier to carry more rounds for the same weight.

Rifle	Cartridge	Cartridge weight	Weight of empty magazine	Weight of loaded magazine	Max. ammunition load*
AK-47	7.62×39mm		slab-sided steel	30-rounds	11 magazines for 330 rounds
AKM	7.62×39mm		ribbed stamped-steel	30-rounds	12 magazines for 360 rounds
AK-103	7.62×39mm		steel-reinforced plastic	30-rounds	13 magazines for 390 rounds

Note: All 7.62×39mm AK magazines are backwards compatible with older AK variants.

10.12 kg is the maximum amount of ammo that the average soldier can comfortably carry. It also allows for best comparison of the three most common 7.62×39mm AK-style magazines.