On the one hand, upgrading an already finished sample is an incomparably simpler task than creating weapons from scratch, but adjusting an existing sample to specific requirements, as it turned out, is not always as simple as it seems, and just drunk the barrel with an automatic, so that it becomes shorter, is not the best option. In order to get a sample of weapons, even being close to the requirements of the Modern competition, many problems had to be solved, and although AKS74U fundamentally does not differ from its full-size progenitor, many details are changed in its design in order to ensure the normal operation of the machine gun and reduce its size.Naturally, the barrel of the weapon was shortened to 255 millimeters in the first place. This step led to the fact that the powder charge of the cartridge 5,45x39 did not have time to completely burn through with all the ensuing consequences. In order for this phenomenon to at least partially compensate, a modular device in the form of a volumetric cylinder was developed. The gas chamber had to be carried back, which required a reduction in the length of the piston rod. In addition, the sample submitted to the competition was also distinguished by sights. So, the rear sight was replaced with a simple reclining, and the butt of the arms was folded up. I repeat once again that this was the first version of the weapon, and not the AKS74U in the final version. Then came the long process of improving these weapons. So, it was decided to trim the barrel with another millimeter 35, butt was replaced with AKMS stock, but the most difficult work was done with the flue unit and the constriction device. In the end, they came to the result that everyone knows, with an even shorter barrel length of 206,5 millimeters. It seems that everything is simple and fast in words, and there is nothing complicated, but if you try to repeat it all, recalculate every detail, and even think up new ones, the result will be quite serious work, maybe not equal to creating a new small-sized automaton. ” from scratch, but very close to that.
Unfortunately, it was not possible to adjust the weapon completely to the requirements of the competition. The reason for this is not that it was impossible to do this, but that if the machine was reduced to the required dimensions, interchangeability with the full-size version of the Kalashnikov assault rifle of most parts would be completely lost, and this would mean high production costs. Therefore, the length of the weapon with the butt folded is not 450 millimeters, but 490 millimeters, but with the butt unfolded, the length of the weapon is 20 millimeters less than the required one - 730 millimeters. The weight of the weapon is also significantly exceeded by 285 grams (2,485 kilograms without a magazine). Due to changes associated with a decrease in the length of the piston rod and other things, the weapon's rate of fire has increased to 700 rounds per minute. In addition, the barrels of weapons differ not only in their length, but also in the pitch of the rifling. In the shortened version of the machine, the rifling pitch in the barrel is 160 millimeters, while in the full-size rifling pitch it is already 200 millimeters. This was done so that the bullet, after leaving the barrel, would better stabilize in flight. It should also be noted that a smaller rifling pitch significantly increases the stress on the bullet shell, and when the barrel is overheated, which in itself is a very, very bad phenomenon, this resistance on the bullet shell manifests itself, becoming one of the reasons for the “spitting” of the weapon. In general, on the one hand, it seems to be the same AK, but already a little different.
It is noteworthy that the Airborne Forces were the first to receive a shortened version of the Kalashnikov assault rifle, although it seems like this weapon was created rather as a weapon of self-defense for those who need a machine gun only as a last resort and is not the main means of influencing the enemy. Naturally, the AKS74U did not take root there and never became the main weapon in view of its specific features. Although it is impossible not to note the flattering reviews about the small weight and dimensions of the weapon, which was quite important in this case. But neither the weight nor the dimensions could compensate for the low accuracy of firing and the small effective range of use. Nevertheless, the weapon received the widest distribution that it could get, and not even where it was needed (police-police, although sometimes they need these weapons, but obviously not in the same quantity as they are now and not ubiquitous). Having received a fairly large distribution, the AKS74U assault rifle was not only used in its original form, but also received a kind of development. On the basis of this machine, a rifle-grenade launcher complex was created, but about this weapon in another article.