If you don't want to use the ball powders, Reloader 17 is an extruded powder that offers the same velocity boost over traditional loads.
Although the "traditional wisdom" about ball powders not being as accurate is something that I'm questioning more and more. I've been using Power Pro 2000-MR and easily exceeding the accuracy specs for Mk262 ammunition. I guess if I were a benchrester I might care a lot more. From a practical standpoint I don't know of any service rifle shooter good enough to separate his/her groups by which were shot with ball or stick powder.
Machine guns are awesome until you have to carry one.