First thing I would do is give away that 777 powder to my worst enemy

Then I'd run 100 strokes of JB bore paste/USP bore Paste with a patch covered bore brush

Get some Shockey's Gold or Pinnacle powder in 3Fg, and stay at 80 grains of powder.

Check all your scope mounts, and try again. You will definitly see a world of difference And no more "Hard Time" seating/loading of the powerBelts. We call that "Hard Time" the 777 Crud Ring[:@]