I use a 55 gallon plastic drum, it holds 450 pounds of rice coal when heaped over the top. I use bags so it's easy, every day I dump in a bag or 2 and empty the ash pan (during the winter), now in the summer once a week I dump in a couple bags and empty the ash. I like bagged coal because I can put 2 tons in one corner, 2 tons in another spot, etc... and I can still have a nice basement for other things like motorcycle projects. 55 gallon plastic drums are great, I have a white/clear one I cut in half and use as a greenhouse during the spring for my seedling transplants, I use another one cut in half for a duck pond, yet another one is wired to my fence and is a feeding trough for the chickens and yaks, in the spring I use a couple (ones that contained food grade product) to hold maple sap for syrup production. I've seen expensive rain barrels at the garden center that are nothing more than a 55 gal. drum with a hose off the bottom and a screened gutter flowing into the top. My buddy has one on a trailer that he uses for a portable waterer for trees out in the field. I get them for free once in a while and I take all I can get, they really come in handy. I wish I had 10 more. I know another guy who uses one as a septic tank for his hunting cabin. One day I might write a book on 101 uses for a 55 gallon drum.
Listen to Richard about cutting the bottom out, I just drilled a hole in the side and it works fine but there is about 50 pounds that will never be picked up.