How Does It Work: Roller Delayed Blowback

Cool Forgotten Weapons merch! Roller delayed blowback originated in the Mauser company R&D department when engineers were attempting to design a roller-locked version of the G43 rifle. They found that when the bolt bounced in automatic fire, the system would sometimes work without being fully locked. With some refinement, this became the roller delayed system, and would have been used in the StG-45 rifle if the war had gone longer. After the war, the system was applied to prototype French arms, then to the Spanish CETME program which eventually became the German G3 rifle. The system would see use primarily as the basis of a whole family of arms from Heckler & Koch, although it has been used in a few other places. Mechanically, the system uses an angled “locking“ wedge to put a mechanical disadvantage on a pair of rollers that must retract into the bolt head be