All submachine guns of AK-100 series have the following operational modes: safety, semi-automatic and fully automatic. Change of modes is achieved by placing a selector lever into a required position.

When placed into its uppermost position, the selector brings the weapon into safety.

The trigger is blocked and the bolt carrier could be retracted only partially - just enough to see through the opening whether there is ammunition in the magazine. The amount of travel the bolt group performs is not sufficient to cock the hammer and send the first round into chamber.

Shifted into extreme low position marked "OD" (odinochniy - single in Russian), the selector brings the systems into a semi-auto operation.

Reloading is based on utilization of the energy of propellant gases which are driven into the gas cylinder located on top the barrel. Upon firing, a portion of propellant combustion gases, pushing the bullet along the bore channel, escape into the gas cylinder, and exert pressure upon the front surface of the piston. The whole group being driven rearward, the bolt turns to the right disengaging its two locking lugs from their recesses in the receiver. The extractor claw removes an empty case from the chamber, and the ejector disposes of it through the opening in the right side of the top cover. As the bolt carrier travels farther, the single-strand recoil spring is compressed, the hammer is cocked and engaged with the auto-safety cocking cam. This cycle completed, the bolt group begins its return travel driven by the recoil spring. The mechanism goes forward, another round is stripped from the magazine and chambered, the bolt turns left to lock the chamber while the bolt carrier releases the hammer from the auto-safety sear. The hammer cocked, the bolt locked - the rifle is ready to fire. The trigger mechanism's mainspring is of multiple-strand type, which lasts longer and offers better performance under adverse conditions. After the trigger has been released, its extension moves forward. The hook in the trigger extension is held by the sear. When the trigger is pulled, its hook moves the sear and disengages it from the hammer cocking cam. The hammer, actuated by the mainspring, pivots forward and strikes the firing pin. The firing pin moves forward and impinges the primer. A shot is fired.

The mere fact of appearance of the AK-100 series is a sure indication that IZHMASH makes a vigorous attempt to regain and expand its International markets. When caliber 5.45 x 39 mm weapons were introduced into mass production to replace the rifles in 7.62 x 39 mm, it was discovered that most of the Russian traditional foreign customers would think twice before placing firm purchase orders. They merely did not trust 5.45 so well as they trusted an old and proven caliber 7.62. In addition 5.45 x 39 mm ammunition was harder to get, while 7.62 x 39 mm was easy to come by. As a result, the volume of exportation shrank considerably. In order to enhance market competitiveness IZHMASH decided to put in line the guns in three calibers: 5.45, 7.62 and 5.56. The Kalashnikovs in 5.56 x 45 mm were created exclusively for export. As a matter of fact, firing the NATO ammunition, AK-101 and AK-102 showed the results noticeably better than 5.45 x 39 mm. First, the case of a 5.56 round is by 6 mm longer and provides propulsion about 20 % greater. Second, quality of cartridge components including propellant, primer and projectile is evidently superior. The geometry of the longer NATO case with least difference between the diameter of the case body and the bullet results in better fire accuracy. Hence, the hit probability as well as the accuracy potential of AK-101 is 22 - 23 % higher than those of the AK74M. Now having the Kalashnikovs in 5.56 x 45 mm IZHMASH seems to be ready to deal with those clients who were traditionally controlled by Western arms suppliers. Anyway, if there is a demand, there must be an offer.