Overall Length : 37.5 inches Barrel Length: 15.4 Weight (empty): 7.2 lbs Cyclic ROF: 600 rpm Capacity: 30rd detachable box magazine Muzzle Velocity: 2850 fps Schweizerische Industrie-Gesellschaft (SIG) was no stranger to the 5.56 round. In the late 60s, SIG began work to develop a lightweight rifle chambered for the 5.56 round. The SIG SG 530 was something of a hybrid rifle. It retained the roller locks of the SIG 510 series, yet added gas cylinder. The adoption of the gas cylinder was intended to prevent the rifle from cooking off it's ammo (Cook-off is a condition where the chamber of the rifle is hot enough to ignite a cartridge.) The SIG 530 was well made, but expensive. It failed to attract any customers, and soon the project was shelved in favor of the SIG SG540.
Photo and Information from: PIERANGELO TENDAS