Gotcha. I had a friend who shot identical to me. It was weird but I was fortunate. Had a problem I couldn’t find. I’d let him shoot. Cost nothing and eliminated me as the problem OR I was the problem. Still have the original barrel? What the heck, you’ve done a bunch. Screw it and screw the old barrel on.I have swapped scopes including mounts, stock, and bipod 3 times. I have not had anyone else shoot it, but the fact that it happened all 3 range sessions and the exact same way each time, I do not think it is shooter. I also had a secondary rifle with me each trip, and it shot as normal, so I could rule out environment.
Be interesting to see what Shilen would say if the problem was gone and you sure would have some vert solid proof. I wouldn’t buy a single thing until every possibility was explored.
I’m still pissed at selling a 220Swift (Sako) because I didn’t explore everything. That was at least 40 years ago and I still have the ass over doing that.