The Cook automatic rifle was a prototype automatic rifle that was designed by Loren Cook.
The Cook automatic rifle was conceived by US Army Ordnance Officer Loren C. Cook in the early 1950s. It was developed at Benicia Armory and was never seriously considered for military adoption, much to the chagrin of the designer, who resigned his military post in protest of the lack of official interest given to his rifle and submachine gun.
The Cook automatic rifle was a bullpup design based around the gas-operated BAR action. The trigger was placed forward of the receiver with a long trigger link running from the mid-section to the rear. Unlike the standard BAR, the Cook automatic rifle was modified to fire from a closed bolt. The overall length of the gun was just 30 inches, whilst maintaining a long barrel length of around 18 inches. The magazines used were standard 20-round BAR magazines.