firearms fall into three distinct categories when it comes to their modes of operation.
All have the similar characteristic of using the energy generated by the firing of a round to actuate the action and effect the extraction and ejection of the spent cartridge case and then proceed to load a fresh round from the clip or magazine. They differ in how they make use of this energy and on which type of energy they rely upon.
In no particular order:
- Recoil Operated guns are generally closed breech or closed bolt guns that uses a mechanical lock to keep the gun in battery at the moment of firing. The sheer recoil (aka action reaction) pushes back on the slide or bolt which will then unlock the mechanism and begin the cycle of extraction, ejection and feeding. A good example of a recoil operated gun is the m1911.
- Gas Operated guns use the immense pressure generated by the burning gun powder to actuate a piston which reciprocates to do the cycling of ammunition. The M-16 rifle is a gas operated firearm. Though mostly used in rifles where greater pressures are achieved, gas operated pistols are also available. the Desert Eagle is one.
- Blowback Operated guns are simple and oftentimes open bolt firearms. This means that there is no mechanical locking of the bolt and it is only the inertia of the bolt and the spring tension which keeps it in place at the moment of firing. The round literally blows back on the bolt to actuate the action. Pros are high cyclic rates without the risk of a cook off and mechanical and manufacturing simplicity while the major cons are a lowered consistency and accuracy. Popular open bolt guns are the uzi and ingram mac10 which are meant for close in combat where the cyclic rate of fire is needed more than bullseye accuracy.
NOTE: While the revolver is indeed a repeater in that you can fire more than one round without reloading, it is not a selfloading firearm as in fact the chambers have all been previously loaded by the operator before the cylinder was put into place.