Todd, here are three questions; hope you'll respond:
1. What do you do with the rounds you don't shoot at the first target? Pull 'em or shoot 'em as foulers?
2. Do you actually have time to shoot those 2 or 3 different loads and go back to your loading bench to load five more cases and shoot your five record shots?
3. It sounds like you "roll the dice" with those last five cases without having tested any of those rounds on the sighter. Why do you assume those will be better than the other 2 or 3 loads you tested?
I will usually take three loads to the first match, will wait until about 30 minutes before the match and take my best guess on my primary load ,temperature wind....
Primary load 15
Secondary 10 rounds two clicks up or down
Thrid 5 rounds opposite of second load
So I will shoot 2 rounds for fouler from the 15
Then I will shoot 2 from the second load, see if they touch
Then 2 from my primary load
Hopefully one of the 2 shot groups will be one hole.Then I will pick the best one to start.
I will usually commit on one of the loads, and shoot a group for record.
If I start good fine, but that doesn't always happen.
So I can shoot 6 shots rather quickly most of the time and try and pick the best load.
If the record group is big, then I start shooting the sighter again with the thrid load, if that is better than I know what direction to go.
Well if I am still lost and have time, then I go back and load 3 more, and shoot.
Most of the time my first load works, and gives me something to work on.
I use all the other rounds for foulers, and sighters.
I have ran out of ammo when I get in trouble, so an extra 10-15 extra rounds on the bench as back up is a good thing.
Hope this makes since
I will role the dice if I have to, but it is a process of elimination.
And sometimes I just don't get it right.
That's benchrest