Thinking of trying a ladder test using varying seating depth instead of powder charge. Is the ladder test a valid method for determining optimum seating depth? Why or why not?
I think more people use the OCW method for determining seating depth. There is no doubt that adjusting the seating depth can change your pressures and velocity a small amount but as long as your charge weight is in the middle of an accuracy node these small changes should not take you out of that node and into a scatter node.
The ladder test is good for determining accuracy nodes but as all of the rounds are fired at the same target and POA your groups may become difficult to distinguish unless you walk down to the target after each round fired or keep extremely good notes when using your spotting scope. The OCW method gives you a different POA for each modification and this at least for me makes it much easier to see the tangible results of my modifications.
Of course I'm still fairly new at this so someone may come along and point out something that I did not know.
"Ladder" tests for seating starting 10 thou off the lands and moving back in 5 thou steps works fine for me. When I see a node I do more experimenting in that range, same as for powder charges.