Ditto to what every one has said. Loose is the way to go for both economical and developing an accurate load for your ML. If you can get BH209 I would seriously look at that powder. If it is to costly to you, then I would look at 777-2F. I was also going to recommend Swiss 3F, but its cost is pretty close to BH209 as well.

Once you develop your load that your ML likes or you are satisfied with. I would purchase a bunch of Lane Powder Vials or speed loaders that you can load up in advance when you either go shooting at the range or hunting.

Ed