- 01: Introduction
- 02: History
- 03: Propellants, Firearms, and Ammunition Development
- 04: Modern Firearms Manufacture
- 05: Small Arms Ammunition
- 06: Evidence Handling Procedures
- 07: Equipment and Instrumentation
- 08: Examination of Firearms
- 09: Cartridge and Shotshell Examination
- 10: Characterization and Evaluation of Fired Projectiles
- 11: Bullet Comparison and Identification
- 12: Gunshot Residue and Distance Determination
- 13: Toolmark Identification
- 14: Communicating Results
- Resources
Blowback Action
Home > Examination of Firearms > Handguns > Autoloading - Semiautomatic Pistols > Blowback Action
Browning .22 caliber pistol
The blowback system is comprised of an unlocked breech that relies on the mass (weight) of the breechblock and the strength of the return spring to prevent the breech from opening and the cartridge case from being exposed during its period of peak pressure.
Low-pressure cartridges are generally used in blowback action pistols; however, there are several pistols that use high-pressure cartridges. These pistol systems tend to be heavier because the slide must be large enough to hold the firearm in battery until peak pressure is reduced. An internal striker or an external hammer is typically present. A visual check should determine the type of firing mechanism.
