You just said it cheek weld I don’t believe your positioning your face in the same place if you are not touching you are not repeatableI guess some details would help!
It's a 30 06 tikka t3x superlite stainless barrel synthetic stock. I used a Dremel to remove extra stock material around the forearm to give it extra float. I can slide several dollar bills all the way back to the receiver without hitting anything.
Strangely it does seem that it's shots 1&3 and 2&4 grouped together more often than not. This group was part of a load development set. The way I'm doing these is I'll shoot one Rd of each load, 5 different loads. The order is 1 to 5, 5 to 1, 1 to 5, 5 to 1. I started doing it this way because I would do each as a 5 shot string giving a 5 minute break between to cool. Now I just do 1 shot every 3-4 minutes and that's adequate to just keep the barrel warm. Again, I have had these groups before and after changing shooting patterns.
I do handload. Here's what they are:
Winchester brass, 3 firings, not annealed
Fed gm210 primers
Sierra pro Hunter 150gr
Started using my hornady comparator to get all my seating depths the same. So for these, they're all seated to be 2.731 base to datum, +/- 0.001
My rest is a Caldwell rock Jr and the bunny ear rear bag. I modified both to give a much more firm grip on my stock and be much more stable. These groups would happen before I did that though.
I don't have a good cheek weld because my scope is sitting too high... Therefore I sometimes find it hard to duplicate the amount of downward pressure I'm placing onto the stock at the grip.
Here is a few targets