Mar 04, 2019 · Steyr STM556. Since the AUG is great but the world prefers the AR-15, Steyr designers in 2012 offered their take on the American design. In short, the STM556 is a short-stroke piston operated AR-15 with a quick barrel changing system directly inherited from the AUG.
Steyr Arms USA 2530 Morgan Road Bessemer, AL 35022 P: (205) 417-8644 F: (205) 417-8647 Steyr Arms EU Steyr International. WARNING This product can expose you to methanol, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov