Got a Ruger M77 MkII where the scope cannot zero due to ring problems. Will the Millet rings with adjustments on both sides of the rings where clamped on the Ruger receiver hold up to big bore recoil?

Your trying to correct a problem with another problem. Find out if its the scope or the receiver / barrel, and send the problem back to get it fixed. Ruger has an excellent customer service department - If its the rifle they will make it right.

likely just bad rings -- call ruger

Sometimes on less expensive rifles the provisions for mounting a scope (D&T'd holes or the dovetails in the receiver) are not in alignment with the bore of the rifle. Some early CZs were a good example. May need a drift-adjustable rear mount to "true things up".

Thanks guys. Part of the problem is this rifle was rebarreled by previous owner, now unknown, so sending rifle to Ruger is a no go. On the rings, tried another pair and had the same problem.

What is it doing? left to right or up down? clint

Clint,
Not enough windage. Completely right on scope and still need 2" after I fired it, just to verify.
May need to get a Leupold with more adjustment range. This is a Burris 1.5-6x.
Max

The Leupold single dovetail set with the windage-adjustable rear will do it.

Be sure the "dovetails" are straight on the reciever to the centerline of the bore. I ran across a 7mm Mag 15 years ago that the front ring would point out about .025 to the right from the rear.This could be the whole problem and maybe have been an un-needed rebarrel to try and get it to shoot!

If you take a triangular file and grind the teeth of the bottom flat you can shift the fixed side of the ring base to give you a windage adjustment. Depending on which way the windage has to be adjusted you may have to turn the rings around so the filed 'fixed' side gives the adjustment in the right direction.

Von Gruff.