C39A

C39A is a designation sometimes used to refer to certain types of ammunition, most commonly associated with Soviet/Russian origins. Specifically, it often denotes cartridges designed for small arms. The "C" in C39A is believed to be a Cyrillic letter "S" (Es), which in Russian military nomenclature often signifies "strelkovoye" or small arms. The "39" likely refers to the year 1939, the year the ammunition type was developed or standardized. The "A" might indicate a particular variant or modification within that cartridge family.

While the exact specifications can vary, C39A is frequently linked to the 7.62x39mm cartridge. This round is famously used in the AK-47 and its numerous derivatives, as well as other Kalashnikov pattern rifles and various Soviet and Warsaw Pact era firearms. The 7.62x39mm round is known for its intermediate power, offering a balance between range, stopping power, and manageable recoil. Its widespread adoption and continued use in many countries have made it one of the most recognizable and commonly produced rifle cartridges globally. The designation C39A serves as an internal or historical identifier for this significant piece of military ordnance.