Nonblowback

Nonblowback refers to a firearm operating system that does not utilize the energy of the fired cartridge's expanding gases to cycle the action. In contrast to blowback or gas-operated systems, nonblowback firearms rely on external mechanisms for their operation. This typically involves manually cocking the hammer or bolt for each shot.

The primary characteristic of a nonblowback system is the absence of automatic or semi-automatic cycling. After a round is fired, the spent casing remains in the chamber until manually extracted and a new round is manually loaded. This manual manipulation is essential to prepare the firearm for the next shot. Examples of nonblowback mechanisms include single-shot firearms and many bolt-action rifles. The term is often used in contrast to semi-automatic or automatic firearms where the firing process itself provides the energy for reloading.

The advantages of nonblowback operation often include greater mechanical simplicity, reduced complexity, and potentially higher accuracy due to the lack of reciprocating parts during firing. However, the primary disadvantage is the significantly reduced rate of fire compared to blowback or gas-operated systems. This makes them unsuitable for applications requiring rapid successive shots. Nonblowback firearms are commonly found in hunting rifles, precision target rifles, and certain types of historical firearms.