To update this thread I did what Bell & Carlson suggested and bedded the recoil lug area. (I also added just a little Devcon 10110 at the receiver screw areas since there appeared to be a little extra space there).
I saw some small improvement in group sizes, but No Joy for the most part.
So...
I came back and bedded the rear of the barrel (not letting the epoxy touch the front of the receiver), and also added a barrel/forearm pressure point - just behind the front sling swivel.
Results are now looking very good. First out yesterday, starting with a clean barrel, and things were looking promising on paper at 100M. At 12 rounds it seemed like it was still settling in, so with temps rising and the range getting a little crowded, I called it a day.
Left it dirty and back out early this morning shooting freshly painted steel at 219 (my Zero distance), 225 and 325 Yards. It's now trying to put the first two shots in the same hole
with 3 shot groups running sub MOA. I did have one unexplained flyer (out of another 12 shots fired), but it was not horrible.
3 at 325 Yds from the bench did 2 3/4" (0.8 MOA) holding 1 mil-dot high. (Optic is a NF 2.5-10x42 with the old style hollow mil-dot reticle. I really like this reticle.)