For those who think that gun ownership can be eliminated:


"Improvised firearms are not solely the province of the criminal element, however; they are also used by insurgents. During the Japanese occupation of the Philippines during World War II, the paliuntod, a type of improvised shotgun, was commonly used by guerrillas and the joint American and Filipino soldiers who remained behind after Douglas MacArthur's withdrawal. Made of two pieces of pipe that fit snugly together, the paliuntod was a simple, single shot open bolt design. The shell was placed in the breech of the barrel, which was then fitted into the larger diameter receiver. The receiver was capped at the breach end, and had a fixed firing pin placed to strike the primer of the shell. When the barrel was pulled sharply to the rear, the firing pin would strike the primer and fire the gun.[5][6] These improvised firearms are still in use by both criminals and rebels in the Philippines.[18][19]"

The US manufactured this type of shotgun and dropped them in Europe during WW II. Two pipes, one nail, one piece of wood.