Bart- I do not argue with your approach. More power to ya. When i work up loads for my rifles my steps are much different and a lot less costly
I load ( same primer,powder,col) 5 rounds of each with 3/10 gn powder difference. Fire round robin style. Pull out 2 tightest groups, Reload 5 more of each same everything as first round. Pick out best of the 2.
Now i jump to 10 rounds of this load (x3) changing powder by 1/10 gn. Shoot again, Pick out best group again.4TH round 10 rounds of that load , only thiing i change is COL. I have never had a issue with it not working for me. I guess in the long run i probebly shoot as many rounds as your method
. I just don't see any reason on the first 2 times out to load 20 rounds. I do 5 different loads to start each time. That would be 100 rounds to test. If i have 1 or 2 loads that do not work, That is 20 rounds i need to either shoot or tear down for nothing.
If a load is going to be something to work with ,it will shine in 5 rounds.