110 FCP HS, chambered in 300 win mag. Setup is as follows:

barrel threaded for brake, and the brake was used/installed during discussion below.
nightforce one piece 20moa scope base
vortex scope rings
vortex viper pst 6-24x50 EBR-1 MOA
Bipod
vortex scope bubble level
Shooting at 100yds

Before seating and torquing the scope rings, the rifle was leveled followed by the scope. Everything was torqued, ensuring level was not lost.

Outing 1 to the range:
15MPH gusts, Federal Gold Match BTHP, 190gr. Took a while to get it on paper, then scope adjustments got the POI closer to the POA, but things seemed erratic. Got Frustrated, went home. 18 shots total.

Noticed that the scope base was loose, so I retorqued this time using blue loctice. Also redid the scope rings with loctite.

Outing 2 to the range (earlier today):
5mph breeze from directly behind, Federal 180gr powershock. Not the same as day one, but much cheaper and readily available so I was fine zeroing with it. 20 shots total.



In the image above, I am pointing at my 1st two shots of the day (today). Then things went a bit nutty. I was ~2inches low and left, so I adjsuted scope for 2" up and 2" right. Shots grouped at the top of the same target, so the "right" adjustment seemed to help and was accurate, but the "up" adjustement seemed to be way too much. (please not that these adjustments yieled only one of the tight grouping of three) I then adjusted the scope down for 1", and that's when things got grey/muddy. I lost all consistency.

I still kept it on the target, but POI and POA never matched. I always used 3 shot groups before making adjustments, and usually 2/3 were OK in the sense that they were close to each other, but the third was always a flier. And the 2/3 that were close to each other never had matching POI and POA.

I am fully prepared to admit that I'm not a pro, but I'm pretty sure that I'm better than this at 100yds! Is there something I can do to verify my setup is rigged properly and functioning as it should? Or, how can I make sure that it isn't me?

Thanks for your help and suggestions.