The Stgw. 57 (Sturmgewehr 57), officially known as the SIG SG 510, is a Swiss battle rifle developed in the 1950s by SIG Sauer and adopted by the Swiss Armed Forces in 1957. Chambered in the powerful 7.5×55mm Swiss cartridge, it uses a roller-delayed blowback system similar to later German designs and is capable of both semi-automatic and selective fire. Built with exceptional precision and durability, the rifle is known for its integrated bipod, distinctive straight-line stock, and relatively heavy weight, which helps manage recoil and improve accuracy. Although more akin to a battle rifle than a modern lightweight assault rifle, the Stgw. 57 earned a reputation for outstanding reliability and accuracy, remaining in Swiss service for decades before being gradually replaced by the lighter Stgw. 90.