Powder measures are used to measure out the desired amount of loose powder. There is no need to weigh the powder. Just find the charge in grains that works for you and measure it out by volume. The advantages of loose powder is you can custom the load more so, and it is a lot cheaper to shoot. As for storing the powder on stand while hunting, some simple 35mm film containers, plastic pill bottles, store bought speed loaders, there are lots of things you can store the loose powder in. All you do is pop the lid and dump it in.

The thing to remember is loose powder in some cases is stronger then the pellet powder so be sure you understand which ones are which and in what percentage...