Redefining perceptions of semi-automatic 5.56 performance; the Hellion from Springfield Armory represents a radically unique and innovative approach to firearms design. Featuring both compact dimensions and capable downrange performance; the Hellion with 20″ barrels offer bullpup fans even more options. With the action located behind the trigger; the 5.56mm Hellion offers extremely compact dimensions even with these longer-barreled new variants. In addition to enhanced ballistic performance with both models; the 20″ version comes standard with a ribbed barrel for maximum rigidity and heat dissipation. It also is capable of accepting a military-pattern bayonet on its integrated bayonet lug. Fully ambidextrous controls and reversible ejection round out the package for maximum adaptability.