Re: Load development ?
Joe you might notice that seating depth adjustments hold the very largest affects to grouping, and without evidence that it relates to tuning nodes at all. In fact, you can't tune into nodes any more with bullets, than primers. These only set size and shape of groups, tuned or not.
Powder is an actual tuning adjustment, as it can be taken right to the kernel, and you can easily tune into and out of nodes with powder.
You can also find best seating with any load, tuned or not.
So seating depth should be prerequisite to tuning, leaving best grouping easier to see(as it would be closer to actual).
When you tune first, you're interpreting grouping by size and shape -that will change with later seating adjustments. So afterwards you would only know if you chose the right size & shape by running incremental powder changes again(starting over).
It's a backwards tail chasing.
In other words, those target groupings will look different once at optimum seating, so how can you really guess which is best before so?
IMO, you can't.
Pick any load there, and adjust seating to shape that load from squares to triangles to bunny rabbits.. You can pick any other load & do the same thing. Then your target choices could be completely different!
I think this is why reloaders end up with such horrible ladders. Their randomly chosen/assumed seating has invalidated the testing.