I now have two black powder rifles, the Kentucky Rifle I bought, and the Musketoon I made. Being black powder, you have to measure and dump powder into them for each shot. I have an adjustable powder measure, but it needs a funnel to fill, and it a pain to use. There are also fixed powder measures available, but I'm cheap and like to make things myself.
For the .45 caliber Kentucky Rifle, I want to use about 70 grains of powder, for the .50 caliber Musketoon I want to use about around 100 grains. Ideally, I want to use the same measure for both just so I have one less tool in my black powder supplies kit. If you've been following along, you know I also have an AK-47. Why am I mentioning that random fact? Because as it happens, an empty casing from my AK's 7.62x39 bullets holds exactly 35.6 grains of powder. That means that two AK shells full gives me 71 grains of powder for the Kentucky Rifle, and three shells worth gives me 106 grains for the Musketoon. Handy, no? You know what would be even handier? Soldering a handle to it to make a dipper :)