AEK-919K was offered as a weapon for crews of aircraft and combat vehicles, as well as special forces of law enforcement agencies.
In the mid-1990s, the Kovrov Machine-Building Plant decided to offer its own design of a submachine gun for a pistol cartridge. The cartridge was supposed to be used standard - 9 × 18 from the Makarov pistol. To reduce the development time, it was decided to use the already developed design of the Steyr MPi-69 submachine gun of the Austrian company Steyr-Mannlicher.
The work on the alteration of the Austrian design was headed by the leading designer of the factory design bureau Pavel Sedov. The alterations were, in general, quite significant. So, in the original sample, in order to cock a submachine gun, it was necessary to pull the shoulder strap, one of the sides attached to the cocking handle, and at the Kovrov plant they left a special cocking handle - it is on the left side of the receiver. The belt attachment was moved to a different location and significantly changed.
The fuse-translator of the fire modes was also changed. While the Steyr MPi-69 has a three-position switch made in the form of a button on both sides of the system, the AEK 919K "Kashtan" fuse-translator received a three-position switch on the left side of the receiver. By rotating the switch, you can put the submachine gun on the safety or select the fire mode - single shots or automatic. You only have to operate such a switch with your left hand.
Received AEK 919K and stock. It was originally a simple retractable stock that was fitted to some variants of the Steyr MPi-69. The too simple frame stock of the original sample was replaced with a stock with a movable butt pad - it can be rotated around the horizontal axis in order to find the most optimal position. For example, when shooting from the elbow, the butt pad can be rotated 90 degrees and rest against the forearm.
The design of the AEK 919K Kashtan is very simple. Automation of a submachine gun works on the principle of free breechblock recoil. The fire is conducted with the shutter open, from the rear sear. That is, when the shutter is cocked, it does not lock the barrel, but is held by the sear in the retracted position. When the release is pressed, the bolt is lifted from the sear under the action of the spring and, moving forward, sends the cartridge into the chamber. The drummer is rigidly fixed to the shutter mirror and immediately after the cartridge has been sent, pricks its primer. A shot occurs, after which the shutter rolls back under the action of recoil, and the cycle of operation of the automation is repeated.
Since a less powerful cartridge is used - 9x18, instead of 9x19 for the Steyr MPi-69, the bolt is lighter. If the weapon is not cocked, then part of the bolt is located on top of the barrel, which makes the weapon more compact with a relatively long (176 mm) barrel. A muffler can be attached to the barrel.
The upper part of the receiver is steel, stamped. The lower part and pistol grip are plastic. Food - from box magazines for 20 or 30 rounds. The magazine latch is located at the bottom of the pistol grip, at the back.
Sights - front sight and a simple reversible rear sight. On the upper side of the receiver, there is a place for attaching a collimator sight.
