Relatively small sized, light weight, high velocity military service cartridges like the ×39mm allow a soldier to carry more ammunition for the same weight compared with their larger and heavier predecessor cartridges, have favourable maximum point-blank range or "battle zero" characteristics and produce relatively low bolt thrust and free recoil impulse, favouring light weight arms design and automatic fire accuracy.  Tests measured the free recoil energy delivered by the ×39mm AK-74 rifle at J ( ft⋅lb), compared with J ( ft⋅lb) delivered by the ×39mm in the AKM. 
Both licensed and unlicensed production of the Kalashnikov weapons abroad were almost exclusively of the AKM variant, partially due to the much easier production of the stamped receiver. This model is the most commonly encountered, having been produced in much greater quantities. All rifles based on the Kalashnikov design are frequently referred to as AK-47s in the West, although this is only correct when applied to rifles based on the original three receiver types.  In most former Eastern Bloc countries, the weapon is known simply as the "Kalashnikov" or "AK". The differences between the milled and stamped receivers includes the use of rivets rather than welds on the stamped receiver, as well as the placement of a small dimple above the magazine well for stabilization of the magazine.