Some guns use energy from blowback to perform the autonomic bolt cycling /reloading process, while others will use a portion of the blowback to operate only certain parts of the cycle or simply use the blowback energy to enhance the operational energy from another system of automatic operation.

This 'blowback' is the predominant component of the recoil. The expanding gas also creates a jet propulsion effect rearward in the barrel against the spent cartridge case. bullet) is still within the gun barrel, the high-pressure propellant gas behind it is contained within what could be seen as a closed system but at the moment it exits the muzzle, this functional seal is broken, allowing the propellant gas to be suddenly released in an explosive muzzle blast. In firearms, a blowback system is generally defined as an operating system in which energy to operate the firearm's various mechanisms, and automate the loading of another cartridge, is derived from the inertia of the spent cartridge case being pushed out the rear of the chamber by rapidly expanding gases produced by a burning propellant, typically gunpowder or, in the case of large artillery, even dynamite. 3 Advanced primer ignition (API) blowback.Other operating principles for self-loading firearms include delayed blowback, blow forward, gas operation, and recoil operation. The blowback principle may be considered a simplified form of gas operation, since the cartridge case behaves like a piston driven by the powder gases. A few locked breech designs use a form of blowback (example: primer actuation) to perform the unlocking function. In most actions that use blowback operation, the breech is not locked mechanically at the time of firing: the inertia of the bolt and recoil spring(s), relative to the weight of the bullet, delay opening of the breech until the bullet has left the barrel. Several blowback systems exist within this broad principle of operation, each distinguished by the methods used to control bolt movement. Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge.

Winchester m14 blowback pellet review