Shutter lag

Ruger P89 pistol with a lock locked in the rear position. The slide stop lever is visible above the trigger.

Shutter lag (shutter stop) - a mechanism that holds the bolt of the weapon in its extreme rear position for the expenditure of all cartridges in the store. It is used in many self-loading pistols and other types of automatic weapons (for example, an AR-15 / M16 assault rifle , a Cz Scorpion EVO 3 A1 submachine gun, an AK-12 assault rifle ). The shutter stopped in the open position, firstly, lets the arrow know that the store is empty; secondly, it speeds up the reloading process: replacing the magazine, you do not need to manually move the shutter to its extreme rear position (take the shutter frame back) to send the cartridge into the chamber.

After the ejection of the last fired cartridge case, the store feeder clings to the protrusion of the slide stop and thereby turns it on. To release the shutter, you need to lower the shutter lag with your finger. In the PSM pistol, the shutter lag does not protrude outward, to remove the shutter from the delay, you need to pull it back all the way and release it. In some samples, the shutter releases automatically as soon as a new magazine is inserted ( Mauser M1910 ^[1] , Heckler & Koch 4 ^[2] ). The Beretta M1934 pistol does not have a bolt delay as a separate part; the bolt stops after the last cartridge has been used up, resting against the rear edge of the magazine feeder.

Shutter lag is often performed in the form of a multifunctional part. So, in the PM pistol, it performs the function of a reflector of spent cartridges; in TT and Colt M1911, the slide stop pin serves as the axis of the barrel earring; in the FN HPDA pistol, the bolt delay axis during firing interacts with the barrel protrusion, providing unlocking ^[3] .