Some people might go on about dropping a light powder charge in the case, topping it off with oatmeal, and then headed to the range to make a mess. *Whatever*
Then there are others that take the opportunity to do some rough testing with several different: powders, charge weights, bullets, primers, etc. This can give the shooter a good idea of what has potential, what doesn't hold potential, where high pressure signs begin to show up with each combination, speeds that different combinations will chrono at, and so forth.
Then, when all 100 pieces of brass have been fireformed and you have a ****-ton of info to ponder while you're on the can, you will then have a better idea of which direction to move forward in. Of course you will have taken extraordinarilly-detailed notes. Right?
Then again, if this doesn't make sense or seems like too much effort... call Quaker Oats
Be safe,
EH