This thread has been long overdue. I am going to pin this thread as a topic for the specifics of long range shooting, as defined by ranges in excess of 500 yards for centerfire cartridges and 100 yards or more for rimfire.
Here's a good video starting point:
This thread (and some others) will serve to extend the classes that are given at the spring and fall shoots.
Welcome from NC! Get some oil on the guts of that build, lots of it and pronto. Part of your issue is that gun is way too dry, all the parts are brand new and haven't "worn in" yet. Lube that sucker up heavy.
Was it a graduated reset or did you switch between maxed out and the lowest functioning setting? Sorry for all the questions, I don't think your problem is actually your gas block, but I can't eliminate it without asking.
Side effects may include burning sensations in the eyes, ears, nose, throat, armpits, genitals, rectum, buttocks, kneecaps, and the soles of your feet. Reports of a temporary loss of a sense of dignity and self-respect have occasionally also arisen.
https://www.fulton-armory.com/FAR-308-Rifles.aspx
You certainly won't lack for suitable sources of help if any is needed to get your build working. I can't wait to see the results!