How accurate is the rifle with the best load you've ever shot in it?
If it is a sub 1MOA rifle, then the ladder may mean something. However, if the rifle is not necessarily that accurate, then the natural size of the group can overwhelm the ladder results. (I hope that made sense)
For example; if the changes of .2gr move the impact point 1/2 MOA, you would see a repeatable pattern with a super accurate rifle/shooter/conditions combination. But if the rifle/shooter/conditions combo is only capable of 1moa (or larger) groups, the 1/2 MOA change would be impossible to discern. If the .2gr change is only moving the impact 1/4 MOA, it would take a seriously accurate rifle to see the difference on a ladder.
I know you don't have a chrono, but without the velocity info. it's really tough to make an informed choice.
I agree with tx_shooter, pick a load and play with the seating depth (I'd probably load some at 36.7 and shoot 3 shot groups with different seating depths). Then after selecting the best seating depth, I'd do a ladder around 36.7 and see what it looked like.
If some is good and more is better, then too much is just right.
My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives