Well, maybe we should look at this differently...
By far the most reliable and full-proof way to ensure that a scope will not move in its rings on a high-recoil rifle, is to eliminate the mechanical possibility of it sliding by resting either the turrets bulge, or the ocular piece cone against the front or rear ring.
On a Blaser R8, in my experience it is most often the turret bulge against the front ring.
Before anyone jumps on the keyboard to say that this puts the scope too far forward, let me ask, and answer, a few questions:
1- Does it affect shooting if the shooter occasionally sees a thin black ghost ring shade around the scope sight picture when taking a snap shot? Answer: no, and it has no effect on sight picture, parallax, accuracy, etc.
2- Can the shooter move the cheek 1/2" forward on the stock during a deliberate shot, to avoid seeing a thin black ghost ring? Answer: yes, and it has no effect on sight picture, parallax, accuracy, etc.
3- Is it necessary to not see a thin black ghost ring to shoot accurately and comfortably? Answer: no, the crisp "perfect" eye relief sight picture is certainly nice but completely unnecessary.
4- What do you prefer: risking seeing occasionally a thin ghost ring around your sight picture, that has no effect whatsoever on your shot, or risking getting kicked in the forehead or the eye by the scope during a snap shot (ask DG hunters...), or even during a deliberate shot uphill (as mountain hunters...)? Answer: I know what my answer is, I have been putting scopes as forward as mechanically possible for 40 years after early painful experiences hunting Chamois in the French Alps...
The bottom line with modern scopes that have great eye relief, is that it strikes me as counterproductive, and quite chancy, to seek to place the scope further back on a DG rifle, in order to get a "target-rifle-on-a-benchrest type" perfect eye relief.
Blaser R8 .458 Lott with Leica scope resting against the front ring. It is mechanically impossible for the scope to move under recoil, and virtually impossible to be kicked in the forehead or the eye by the scope under recoil, even in the most hurried snap shot or the most uphill shot, and the forward position of the scope has no downside whatsoever except possibly showing occasionally a thin black ghost ring around the sight picture that has zero effect on shooting.
My recommendation: rest the scope mechanically against the ring, it will never move and never hit you. And by the way, in most cases we are taking about moving the scope forward 1/8", 1/4" or 1/2" inch, which is essentially nothing. Try it, Glenn Slaven, just to see how the sight picture looks, you will be happily surprised...
PS1: admittedly, this method is not always possible with all scopes and all mounts. For example older Leupold scopes could not rest the ocular piece against the rear ring, because there was no change in tube diameter before the zoom ring, and resting the zoom ring against the rear mount ring would obviously prevent it from turning.
PS2: as to ring lapping, sorry to rain on the parade, but I have seen more folks destroy their rings (over doing it) than actually fix the problem. Beside, I doubt very much that Blaser rings are not concentric...
