I've floated the barrel by sanding out the stock forward of the front lug. I had to trim one thread off the screws to get them to tighten (28 in. lbs) per screw. I did tighten the rear lug first. It just seemed logical.
I had a piece of the "Corian" left over from my new cabinet top, cut and sanded it and fit it between the two lug pockets in the stock to strengthen it. Again, it seemed logical in the flimsy stock. (I'll post some pixs if you'd like).

The groups are 2" to 3" @ 100yrds, (Vertical alignment) but never in the same place. I'm shooting Hornady SST 250 Low Drag with 90gr of Triple 7. Before I pulled the stock to clean the gun, I got groups 1" to 1.5".
It's gotta be the stock.