Sig’s Roller-Delay Blowback – Overcomplicated Swiss Brilliance

    What do you get when you combine German inspiration with Swiss design and machining? An arguably overcomplicated, yet completely brilliant design. Designed after the Second World War, the Sturmgewher 57 is a roller-delayed blowback design with some rather interesting design items.

    Unlike weapons before it, the STG-57 (and its civilian-oriented cousin, the PE-57) features an in-line stock, which helps with controlling the recoil. Chambered in 7.5 Swiss and .308 for us ‘Mericans, the weapon uses roller-delayed blowback to operate, but interestingly is over-built. As Ian at Forgotten Weapons shows, the parts are beefy, designed with battle rifle calibers in mind.

    Perhaps most notable on the firearm is the significantly different extractor and ejector assembly. Rather than having two separate parts (as is most common), the weapon uses a single assembly. It a brilliant little design, with significant material to both handle the rough extraction of a roller-delayed blowback and the ejection cycle. It uses an articulating pivot to sweep the rear of the brass off the bolt face rather than rotate it out of the action. In slow-motion, this makes ejection seem opposite to all of us used to the AR and AK platforms. Combined with the unusual hammer assembly, folding sights, and movable bipod, its an uncanny design.

    Ian puts the weapon through its paces with the usual full strip and breakdown. This one is a do not miss for anyone appreciating weapons design.


    Nathan S

    One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

    The above post is my opinion and does not reflect the views of any company or organization.