Oldpapps asks me:
Is it not your opinion that the best accuracy for a given weapon is achieved by fine tuning the load for that weapon?
Yes, but only if it's worth the expense of doing it.
How many shots per test group for each load does it take to have 99% confidence that one load's 3% more accurate than another?
Note also that if you shoot two groups with the same load and they're not within 5% in size, you're not shooting enough shots per group for them to be at least 95% meaningful. Best example of this is shooting a few 5-shot groups then averaging their size. The average is not the accuracy of the load. The accuracy is at least the size the largest group is. If you fired one 20-shot group instead of four 5-shot ones, that 20-shot one will be bigger than the largest 5-shot one.