A new ranged weapon: "amethyst bow" (Name is up for change)

The "Amethyst Bow" is a device made with redstone and amethyst and using "amethyst charges" to essentially shoot lasers. It should be faster than a bow and be an automatic weapon (There is already "charge-release" and "charge-hold") and no falloff. But it has shorter range and lower damage. The "automatic" shooting can be changed to something more unique if that does not fit the theme of Minecraft. The reason I suggest this is because not only do we need a use for amethyst, but we only have two ranged weapons and it would be fun to have a third. Also, it does not necessarily have to shape like a bow.