Blowback (firearms)
Videos
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 propel
The .380 ACP Colt Model 1903 Pocket Hammerless uses simple blowback. The mass of the slide is enough to delay opening of the chamber until pressure has dropped.
7.62x51mm NATO rounds from a delayed blowback firearm. Note the scorch marks from the fluted chamber
Cutaway model of the chamber with gas relief flutes (left) and roller-delayed action of the G3 battle rifle
Exploded view of primary components for bearing delay bolt carrier group
Heckler & Koch MP5
Videos
The Heckler & Koch MP5 is a submachine gun developed in the 1960s by German firearms manufacturer Heckler & Koch. It uses a similar modular design to the Heckler & Koch G3, and has over 100 variants a
Blowback (firearms)
…the anti-bounce mechanism is omitted by Heckler & Koch on their roller-delayed blowback firearms chambered for pistol cartridges. Heckler & Koch's MP5 submachine gun is the most common weapon still in service worldwide using this system. The Heckler & Koch P9 semi-automatic pistol, CETME Ameli light…
Heckler & Koch MP5A3
HK MP5 markings on the firearm
A view through the MP5's iron sights
An MP5A2 with an aftermarket "dedicated forend" tactical light-equipped handguard. Also note the fixed stock and jungle style magazines.