Crank-operated Arcane Scattershot

This two-handed firearm has a large hand-crank attached to the receiver. It functions as a Wand of Magic Missiles, shooting the missiles from its stubby barrel when fired. To use multiple charges, you turn the crank several times before aiming and firing.

This contraption is quite unstable however, and depleting its amethyst power source has a chance to render the weapon inert. If you use the final charge, roll a d20. On a 1, the firearm becomes non-magical.