bruce_ventura
Well-Known Member
First I would measure the gap in the rear ring under the straight edge using feeler gauges. How much are we talking here? In terms of the approach to fixing the problem, there's a big difference between 0.004" and 0.040".
If the gap is small, lap the rings and proceed. If it's large, you can bed both rings using JB Weld, using the same general process used to bed a base to a receiver. Be sure to apply mold release (furniture wax or shoe polish) to the scope tube. there is a YouTube video on this process.
I would also recommend checking the existing boresight alignment. Mechanically center the reticle and mount it in the rings. Tighten the ring cap screws just tight enough to hold the tube against the saddle. Sight down the bore and through the scope at a grid target to determine the boresight alignment error. Again, if the scope is aiming low, lapping will likely improve the boresight alignment.
FYI, Weigand sells a Weaver rail adapter for $60. No drilling required. http://www.jackweigand.com/Ruger-M77-MKII-Rifle-Scope-Mounts-No-Drill.html
If the gap is small, lap the rings and proceed. If it's large, you can bed both rings using JB Weld, using the same general process used to bed a base to a receiver. Be sure to apply mold release (furniture wax or shoe polish) to the scope tube. there is a YouTube video on this process.
I would also recommend checking the existing boresight alignment. Mechanically center the reticle and mount it in the rings. Tighten the ring cap screws just tight enough to hold the tube against the saddle. Sight down the bore and through the scope at a grid target to determine the boresight alignment error. Again, if the scope is aiming low, lapping will likely improve the boresight alignment.
FYI, Weigand sells a Weaver rail adapter for $60. No drilling required. http://www.jackweigand.com/Ruger-M77-MKII-Rifle-Scope-Mounts-No-Drill.html
