Slam-fire shotgun

3D Model

This type of improvised firearm known as a ‘slam-fire’ gun relies on the user of the weapon to force the barrel onto the firing pin inorder to fire the gun, this weapon can be relatively easy to make as it does not require complicated trigger mechanics and obscure or diffucult to find parts, and in my opinion would have a niche as a craftable in a post apocalyptic survival situation. this weapon concept can pretty much be applied to any type of ammunition that uttalises a percussion cap to discharge the bullet and so can the adapted into a rifle, pistol, ect, so just reduce the size so that the bore will fit the ammo you want to use.