What is blowback?
Q: What is blowback?
A: Blowback is a system of operation for self-loading firearms that utilizes the energy from the motion of the cartridge case to push the breech open and eject spent cartridges.
Q: How does blowback obtain energy for operation?
A: Blowback obtains energy from the expanding gases created by the ignition of the propellant charge, which pushes the cartridge case to the rear, providing energy to operate the firearm.
Q: Are there different types of blowback systems?
A: Yes, there are different blowback systems that exist within this broad principle of operation, each distinguished by the methods used to control bolt movement.
Q: Is the breech locked at the time of firing in most actions that use the blowback operation?
A: No, in most actions that use blowback, the breech is not locked mechanically at the time of firing, but the inertia of the bolt and recoil spring(s) delays opening the breech until the bullet has left the barrel.
Q: Are there other operating principles for self-loading firearms besides blowback?
A: Yes, there are several other operating principles for self-loading firearms, including blow forward, gas operation, recoil operation, revolver, Gatling, and chain.
Q: Can locked breech designs use a form of blowback to perform the unlocking function?
A: Yes, some locked breech designs use a form of blowback, such as primer actuation, to perform the unlocking function.
Q: How does the cartridge case behave in the blowback principle?
A: The cartridge case behaves like a piston driven by the powder gases in the blowback principle, which is considered a simplified form of gas operation.
