If you even watch fighters from time to time, not to mention the in-depth knowledge of small arms, then you must have seen a slide delay. True, not everyone knows what it looks like, what it is for, what advantages and disadvantages it provides. Such ignorance should be addressed.
What it is?
When firing from different types of automatic and semi-automatic weapons (both pistols and machine guns, shotguns), with each shot, the bolt moves back. In this case, the fired cartridge case is thrown, the cock is cocked (do not confuse with the trigger), and a new cartridge is sent to the barrel. This happens as long as there are cartridges in the store.
As soon as the last of them fired, the shutter does not return to its original position, but as if stuck in place. This is a shutter lag.
On different types of weapons it is carried out in different ways, and sometimes not at all. Among the pistols you can bring a Makarov pistol, TT, HK4, Mauser M1910, Beretta M1934, among submachine guns - the Slovakian Scorpion, and among machine guns - M16 and subsequent modifications, as well as AK-12.
In some modern weapons, the bolt delay is even modified by a special mechanism that throws the magazine after the last cartridge was sent to the barrel. This is not very convenient (with intensive movement during the battle it is not always possible to find a lost store), but it saves an extra second - you do not need to first disconnect an empty store to insert a full one. But this is found in relatively few weapons.
What is needed for
What is the purpose of the slide delay? Usually, in order to send a cartridge to the magazine, it is necessary to twist the shutter. It would seem - no problem, because a trained person takes a split second. However, as practice shows, in battle this can be a real obstacle. On the one hand, a person may simply be confused and do not understand why the machine, in which the full store is inserted, refuses to shoot. On the other hand, on some types of weapons it is quite difficult to distort the bolt, for example, with gloves. A striking example is the well-known M4. With a battle shake, it can be quite difficult to twist the shutter.
The gate delay serves to solve this problem. To send a new cartridge into the barrel, you do not need to juggle the shutter. Some weapons are automatically removed from the delay as soon as a new store is inserted into them - the most convenient, but at the same time difficult option. In other types, you need to click on a specially provided button that removes weapons from the slide delay.
That is, the fighter saves fractions of a second by jerking the shutter. In modern fleeting battles that take place not in forests or fields, but in cities or even premises, such a time saving can very well save a person’s life.
An additional function is to signal the shooter that the cartridges have run out and you need to insert a new magazine, and not continue to pull the trigger, hoping to take a few more shots.
Advantages and disadvantages
What advantage is provided by the shutter lag of PM, TT, AK-12 and other weapons, is already clear from the above.
Alas, there is a drawback. It consists in the accidental ingress of foreign objects (debris, dirt, dust) into an open mechanism - not protected, as usual, with a shutter.
The fact is that at the moment when the store is empty, and the soldier loses the ability to conduct further fire, the best thing he can do is move to cover, fall or at least sit down, making it difficult for the enemy to fire. It is at such moments that it is very difficult to ensure that the weapon is protected from dirt and debris. And this may well lead to the fact that it will simply jam. Moreover, it can be put in order only by partial or even complete disassembly - there will simply not be time for this in battle.
However, this happens relatively rarely, so the advantages of the shutter lag (saving time when reloading and telling the shooter about an empty store) outweigh the only drawback.
Finally
This article describes what a slide delay is and what are the most well-known weapons samples. Now you have an idea of the main pros and cons of such a design solution.