I take one brand of brass, whatever I have plenty of, usually Win, inexpensive and easy to get. Load test rounds in three shot group's and load a full box with just sticking in the extra rounds wherever. Might change powders a couple times which needs another full box each time. Once I find the load, I want I do five round groups just because! Then when I'm satisfied, I load 20 rounds. After shooting half I load up another box of the same thing. Thats my using rounds and don't care to let it get below about ten rounds. I am not a competitive shooter or I'm sure I'd keep more on hand.