Nobody here is trying to be condescending. Since we don't personally know each other and aren't loading and shooting the rifle, all we can do is throw out suggestions based on the clues you provide. So, don't take anything personal.
Nonetheless, we're all glad you got it worked out and welcome to the forum.
I was able to stretch the rifle out today for the first time. I wanted to shoot some groups at the farthest distance in Dad's hay field (485yds corner to corner). Mirage was so bad that I gave up on that idea. I got sighted in at 200 and then backed it up.
Entered the data in my smart phone app (Strelok) and came up with 7 moa adjustment for a 485yd shot. Dialed 7 moa up on the scope, wind was blowing straight at me. Shooting off of a bench in my four wheeler trailer, with bipod and rear bag. Held right in the middle of one of the milk jugs I had placed at the target stand. Bang, dead milk jug first shot.... Damn that seemed to easy. Hopefully next weekend I can get out and shoot farther.
I don't buy into the "bad brass" issue in this instance. ...not that it can't happen.
I did state that it was "a longshot and rare", but if I have tried everything, and considering the rifle for defects, it would be wise to try different brass if you were working with one brand of brass of the same lot. That was the context of my advise and cant see the downside to trying it under those circumstances. It did happen to me once, and I was getting high pressure with the bad lot. I don't know why, but I suspected off spec internal dimensions. I didnt pursue it once I was getting good results with a different lot.
"Let us speak courteously, deal fairly, and keep ourselves armed and ready"-T. Roosevelt
Just thought I'd let everyone know I bought a case comparator and measured some of the brass. New Laupa brass measures about .009'' smaller then fired brass. Take it however you like, but I think that a case that has to stretch that much will show some signs of pressure.
I have not got a chance to shoot it with a different lot of brass yet. The gun shoots good with fired and resized brass though. I got a chance to stretch er out a little farther last night. Set up some jugs filled with water at 655yds. Layed in the back of the truck shooting off the bipod. Punched the info into my phone and it said 12moa of adjustment. First shot about 12 inches high. I ended up taking 2moa adjustment off and we were right on the money. The wind was blowing around 2.5-3.0 mph so I had to hold a little wind, but once I got it figured out I was hitting the jugs nearly every shot.
I think I need to check my 200yd zero because I don't think that the program would've been off that far. Thanks for reading, I think I've finally got this rifle figured out.