I would argue that to sit down and fire 30 or 50 shots in a row in many cases would not be statistically valid since that may not be how the rifle would be used. The heat build-up would that would not exist if you fire 1-3 shots would be an additional variable. If you are not satisfied with a 3 shot group, but that is what you would likely shoot, you would probably need to measure and analyze the first 3-shot groups from multiple days, in which scenario, you now need to add weather as a variable in most cases.
Me? I would be happy with a few 3-shot groups under a MOA, and more than happy the closer I get to 1/4 MOA @ 100 or 200 yds. And not try to overanalyze it.