AK and AK-47
AK abbreviates the Russian designation Avtomat Kalashnikova. The number 47 identifies the foundational 1947 design reference. In general conversation “AK-47” often expands to cover the entire visual family, but object-level description benefits from a narrower use. Many later rifles are AKM-pattern, AK-74-pattern or national derivatives rather than early AK examples.
AKM
AKM is commonly expanded in English transliteration as Avtomat Kalashnikova Modernizirovanny: the modernized branch of the design. The designation is closely tied to the 1959 stamped-receiver revision. Riveted trunnions, pressed receiver contours and a distinct set of smaller details separate the AKM system from mature milled AK production.
AK-74
AK-74 identifies the later generation associated with 5.45×39mm. It preserves the broad operating arrangement but is not simply a renaming of the 7.62×39mm AKM. Magazine geometry, muzzle form and component standards reflect its own design branch. The marked chambering remains more reliable than an inferred label.
Type 56
Type 56 is a Chinese national designation applied to a family of Kalashnikov-pattern rifles. Examples exist with milled and stamped receivers, so the designation alone does not settle receiver construction. Configuration-specific sight, stock and marking details help narrow an identification. The name should not be used as a quality shorthand.
RPK
RPK denotes the squad-support branch of the pattern. The family uses a heavier-profile configuration, a reinforced receiver pattern on common examples and characteristic furniture. It is related to the rifle family but has a different service role. “RPK-style” furniture or a large magazine does not transform a rifle into that historical category.
Construction and interface terms
- Trunnion
- A structural block joined to a stamped receiver shell. The front trunnion carries major barrel and locking interfaces; the rear trunnion supports the stock attachment on common patterns.
- Long-stroke gas piston
- An operating arrangement in which the piston and bolt carrier travel together through the operating cycle.
- Rock-and-lock magazine
- A magazine interface in which the front lug is engaged and the rear catch secures the body as it pivots into place. The term describes geometry, not a loading procedure.
- Furniture
- The stock, pistol grip and handguards, traditionally wood but also made from laminate, phenolic composites and polymers.
- Side rail
- An external mounting interface fixed to the receiver side on many configurations, intended to support a removable optic bracket.
Words such as “variant,” “pattern” and “derivative” acknowledge family resemblance without claiming exact identity. The U.S. import glossary covers commercial labels separately, while the variant guide combines designations with origin, chambering and receiver form.