With just the information given: First WOW on the velocity! Its a wonder the scope remains in place not to mention your shoulder.;)
When I had those kinds of problems the solution was degrease, degrease, degrease. Then tighten ring screws (on the scope - burris sig. bases) until the wrench that came with looked like it was threaded instead of straight. I hawg'd the squat out of things.
NOTE: Be careful to NOT crush the tube.:eek:
Keep us posted, OK?
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!