The original Liberator was a 45 ACP from the WWII era. Those are valued highly by collectors and very expensive. I've heard of a similar design in 9 MM from the Viet Nam era but never seen one. It seems they were made up as cheaply as possible with the intent of distributing them to the general populations who would then use the gun to shoot an enemy soldier and take his better weapons. Very few, if any, were actually used as intended.