Looking at your data, what did you do with the powder charge? How did you come up with the powder charge you used to test with the seating depth?
It looks like the rifle is not in it's accuracy node yet, and you are trying to fine tune the load that isn't in tune yet. Work the powder charge first, then the seating depth (if you are going to do the seating depth). I do not tune to the seating depth. I tune the ammo with the powder charge to the harmonics of the barrel. I know where most bullets need to be seated to shoot well, and go with that seating depth first. If it's a VLD, it WILL shoot best just touching the rifling (not jammed, not off the lands, but leaving a faint scratch mark on the ogive of the bullet after chambering and extracting a loaded round). If the rifle is a custom 300WSM, it should do 1 moa easy, and with the right shooter and loads, should be able to do 1/2 moa or better. The WSM cases are finicky to load for. So, they do take more work with load development. This is why it's important to start with the powder charge first.
But also, you haven't said anything on how you are shooting the groups (bipod, sand bags, lead sled, etc). Is the rifle bedded? What is your method for testing these (bench, prone, etc).
Shooting groups is not as easy as just pulling the trigger. You have to eliminate you as a shooter from the group errors. Meaning, I stay on the rifle the entire time during one group test. I shoot prone and sink into the rifle, snug into my shoulder, firm cheek pressure, and stay exactly in position on the rifle throughout the 3-5 rounds of each group. I do NOT come off the rifle at all. If you come off the rifle and change up your shoulder location, it will recoil different, and change the point of impact, which will effect your group. Sure, we are not talking much POI shift, but enough to open up a group to give you false data. I put all my test rounds right below my right hand so I can cycle the bolt and chamber the next round without coming off the rifle. Plus, if you are not naturally lined up with your natural point of aim, the rifle will be recoiling all over the place and hopping to the sides. I know shooters that I compete with that can not shoot a good 5 shot group if they had to. But they shoot targets at long ranges under stress extremely well.
Take a look at this target below. This is what I call a text book load work up. This was a custom 243 Win competition rifle shooting the 115 DTAC bullets shot at 300 yards. The only thing I am doing to the ammo is increasing the powder charge in small increments with each load.
Load A is in the middle, Load B is top left, Load C is top right, Load D is bottom left. All were shot in order, all rounds of Load A first, then all rounds of Load B, etc. Load A was an open group, and I only shot 4 rounds, since I knew this was not the load it liked. Next was Load B, top left. It had 3 rounds nice and tight, but were stringing the groups up and down. I knew immediately that the next load, Load C, top right, should be the accuracy node. So, I made 5 good shots, and it put them into a nice 1" group at 300 yards. Load D opened up again, and shows that I passed the accuracy node, so I only shot 4 rounds. Load work up complete in 18 rounds!!! (Plus a few sighters at 100 to get on paper and such). This normally doesn't happen this quick, but sometimes it does. 1 out of 4 rifles I have to make a return trip to the range with for a second range session to fine tune the load up, and/or start over with a different powder. But 3 out of 4 rifles, I can get right on the first trip with the proper loads.