Blowback is a term that refers to a particular system of operating self-loading firearms. With blowback systems, pressure is created by the detonation of gunpowder within the casing of the gun. This in turn propels the ammunition within the barrel of the gun outward. There are a variety of blowback systems used across a wide range of firearms, the distinguishing characteristic being the particular method of control for the bolt movement in each kind of firearm. Blowback is a very common action used in many modern weapons and is most common amongst smaller caliber semi-automatic and automatic guns.
There are many popular examples of blowback firearms. Some of them also happen to be some of the most highly sought after collector’s guns. Some of the most widely known include the Marlin Model 60, the Winchester Model 1905, 1907 and 1910, the Burton Model 1917, the Remington Model 51.
There are three primary categories of blowback firearms: simple blowback, advanced primer ignition (API) blowback, and delayed blowback. Outside of these main categories, there are other blowback systems including floating chamber blowback action, primer actuated blowback, and case setback. Within the category of delayed blowback systems, there are a variety of forms of blowback action. They include:
Blowback systems of operation for firearms have been in existence for over 100 years and have been exemplified in some of the most famous and widely produced guns in history. As with many other firearms, the concept itself was developed to address specific needs, whether for military or sport, over time. It is, for instance, a very practical system for guns that employ lower power cartridges with lighter weight ammo. What is interesting about the history of the blowback system is the way that the concept has come to bear on so many different varieties of weapons.