How Does it Work: Long Recoil
Forgotten Weapons
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2m 57s
Long recoil operation is one of the most mechanically interesting of the main firearm operating systems. When the gun fires, the recoil energy generated forces the barrel to move rearward, and the bolt remains locked into the barrel until the two reach the full length of travel (the length of the whole cartridge). At that point the bolt is held rearward and the barrel unlocks and moves forward under pressure from a return spring. The empty cartridge case is held in the bolt face, and the barrel pulls forward off the front of it. An ejector kicks the empty case out when the barrel is fully clear, and when the barrel has returned to its firing position a trip releases the bolt, which moves forward under pressure of a second return spring and feeds the next cartridge into the chamber.
Long recoil system are very safe, as they allow the longest time of any system to let pressure vent from the barrel before unlocking. They are also mechanically complex, and tend to exhibit higher than normal felt recoil. The system was employed successfully in a wide variety of firearms including light machine guns (the Chauchat), rifles (the Remington Model 8/81), shotguns (the Browning Auto-5 and Winchester Model 1911), and handguns (the Former Stop). All of these date from the early 1900s, when designers were still exploring ways to safely and reliably build self-loading firearms.
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