Accuracy evaluation through testing with 5-shot groups is dubious at best. I attempt to start to address that here: http://www.bisonops.com/2019/08/17/rifle-ammunition-load-workup/ The long and short is that most 5-shot groups are statistically not different thought different loads may produce results that look convincing. I think that a better approach is to establish a baseline and work from there. I'm not sure the best way to do this. Establishing a baseline is time consuming and not as satisfying as shooting a few 5-shot groups and formulating conclusions from those, but we're really just kidding ourselves. Better to commit to starting with 20-30 shots in a single group, or several 5-10 shot groups that are then merged together. Then the question is how to best differentiate one load from another relative to this baseline.