John Anderson was a Korean War veteran who became interested in developing a high capacity, selective-fire combat shotgun for military use. He designed what became known as the Pancor Jackhammer, a fully automatic, gas operated, blow forward, drum fed shotgun. Three working examples were made, two tested to destruction by HP White Labs, and one which Anderson retained for himself. The project ultimately failed for lack of funds when the military decided not to pursue its development – but not before Anderson began working on an improved Mk3 version. The Mk3 never reached completion, but what we have to look at today is a partially completed prototype of it. This gun never had a firing mechanism installed (and appears to be unfinished inside as well), but is registered as a transferrable machine gun.