Stiff return spring from a firearm, it's the part that makes the bolt bounce back.
Fully-automatic machine guns need a way to absorb the recoil caused by a firing bullet to avoid sending the weapon rocketing backwards out of control. The earliest machine guns used springs to form a recoil-based system. A "breech bolt" was pulled back to depress the rear return spring. When the trigger is pulled, the spring is released, sending the breech forward and into the cartridges, where they ignite and fire the projectiles. The bullet pushes back on the bolt and barrel, sending said components back. As the bolt recoils, a barrel spring pushes against the barrel, preventing it from moving any farther back, while the bolt again meets up with the rear spring. If the trigger is still activated at this time, the rear spring fires again, and the whole process is repeated. Springs are also used in modern blowback systems, where springs are also used to drive the bolt forward.
Can be obtained from dismantled automatic weapons or purchased from return spring manufacturers.
- All Assault Rifles
- All Light Machine Guns
- All Submachine Guns
- Likely scavenging locations: