The Sieg automatic rifle was a bullpup automatic rifle designed by Chief Gunner's Mate James E. Sieg of the US Coast Guard.

[2] A two-finger double trigger selected between semiautomatic and fully automatic fire.

The barrel came with a unique muzzle compensator that could be turned off for use with a flash hider or grenade launcher without interfering with the installation of a bayonet.

Recoil gently threw the barrel of the Sieg rifle downward, not upward.

The compensator was extremely effective; it also enabled the user to fire the rifle with one hand.