you would need some way of measuring pressure. a pressure trace will let you compare pressure readings from shot to shot i used a pressure trace like greg had on my 25 wssm and was able to compare the pressure readings from shot to shot. you would also need to make sure the powder all came from the same container as different lots of powder can vary slightly. you must also maintain a consistant barrel and air temperature. exact neck tension on the bullets would also be a factor. once the difference or lack of is proven on one powder and charge weight you would need to change the charge weight by a small amount and see if the results stay the same. then reapeat the same increment and direction of charge weight change and do so multiple times. then do the same with multiple powders just to be sure that the results are true in general or just in certain situations. all in all cci200s are hard to beat. not always the best with every load but so far always good with ever load