Gas block, piston and carrier
The AK pattern uses a long-stroke gas-piston arrangement. The piston is attached to the bolt carrier, so those elements move as one operating group. The gas block diverts propellant gas from the barrel into the gas system, while the gas tube guides the piston and supports the upper handguard on common configurations. The receiver cover encloses the moving group from above.
This arrangement is a useful classification feature because the piston and carrier relationship is visually and mechanically distinct from short-stroke systems. The description explains how parts relate; it is not a procedure for cycling, removing or altering them.
Bolt body, lugs and extractor
The bolt rotates as it locks and unlocks. Its locking lugs engage matching surfaces in the front receiver structure: integrated geometry in a milled receiver or the front trunnion in a common stamped receiver. The extractor retains the cartridge rim during rearward movement, and the ejector is part of the receiver-side arrangement that directs the empty case outward.
The firing pin sits within the bolt, retained according to the specific pattern. Small dimensions and heat treatment matter, so parts that look similar are not necessarily interchangeable. Condition and safe operation cannot be judged from a family-level description.
Receiver, trunnions and spring assembly
The receiver supports the operating group and ties the barrel, magazine interface, controls and stock together. In stamped construction, front and rear trunnions carry concentrated loads and attachment points. Internal rails guide the carrier and support the bolt's travel. A recoil-spring assembly returns the operating group forward and is retained at the rear of the receiver on the common pattern.
The magazine catch, trigger guard and selector lever occupy the lower and right-side receiver areas. Their geometry differs across variants. This page names those parts only; it does not explain replacement, adjustment or repair.
Trigger group and sights
The trigger group includes the trigger, hammer, disconnector and associated springs or retaining elements. Civilian semiautomatic configurations differ mechanically from military service configurations, and a visual resemblance does not erase that distinction. No conversion information is provided here.
The sighting system commonly combines a protected front post with a tangent-style rear sight leaf. The rear assembly is mounted forward of the receiver cover, while the front base sits near the muzzle. Sight radius, graduations and protective forms vary by model. The optics page explains the separate side-rail interface.
Muzzle devices and external fittings
Historical configurations include plain muzzle nuts, slant compensators and larger brake forms. Their shape and attachment are pattern-specific identifying features. The cleaning rod, sling loops, bayonet-related fittings and handguard retainer are additional external cues that can help distinguish an origin or era.
Boundary: parts are described for vocabulary and identification. For service, condition or compatibility questions about a particular rifle, use an appropriately qualified professional.