View Full Version : Ruger M77 Scope Mounting Question

May 6, 2008, 03:01 PM
I have a new, M77 Ruger MKII Stainless Synthetic and it came with scope mounts from the factory that fit the intregal bases in the receiver. They look so different from the usual "Weaver Type" that I am used to I wonder if there is anything unique to attaching them. Any words of advise or anything that I should know about them? Thanks alot!:)

May 6, 2008, 03:16 PM
A few htings to make sure of:
1- Ruger rings come as matched sets, so do not mix and match them, and make sure they are assembled the same way they came apart.
2-Remove the large nut from the scope ring crossbolt, clean the threads with alcohol or GunScrubber, then put a dot of blue threadlocker on the screw threads and reassemble.
3- Put the large bolt head on the off side of the rifle, so you don't bark your knuckles when trying to reload real fast sometime. Tighten the bolt fairly tight, but don't try to break it.
4- Clean the scope ring screws and screw holes with alcohol or GunScrubber, put a dot of blue thread locker on the screws, and a dot of threadlocker in the bottom of the rings.
5- Lay the scope in the rings, place the scope ring tops over the scope, insert the screws but do not tighten yet.
6- Align the scope crosshairs and set the proper eye relief for you. Tighten the scope ring screws gradually and evenly, tightening one side, then the other about one turn at a time. If you tighten one side completely before tightening the other side, you will torque the scope in that direction, and you will have a large gap between top and bottom halfs of the rings on one side.
7- Once the screws are tight, go back and check screw tightness again, wipe off any excess threadlocker, and let it sit for a few hours.
8- Go shooting. Repeat often.

May 6, 2008, 03:34 PM
Ruger rings are very strong and a good design. That said, if there were ever a set of rings that need to be lapped, that's Ruger rings. It would be a miracle to mount a scope in Ruger rings and not leave ring marks or even a bent tube. I've seen it on every Ruger I ever dealt with until I started lapping them. I even had one pair that weren't totally machined out and there was a ring at the edge. That ring actually dented the scope tube because I didn't notice it until it was too late.

Lap em. In my opinion every set of Ruger rings should get lapped.

May 7, 2008, 05:08 AM
Ditto on lapping them.


May 7, 2008, 05:42 AM
Thanks for the helpful responses. Forgive my ignorance but what is the correct procedure for "lapping"? I know that it is a procedure to smooth out the rough machining but what do you use and how exactly do you do it? Thanks for putting up with my ignorance on this subject.:o

May 7, 2008, 05:54 AM
If you go to Midwayusa and look at their lapping kit it will be pretty obvious how it works. Or if you have a 1"outside diameter bar or pipe you can use that and some fine abrasive paste(even toothpaste) and make it work. You barely tighen the rings halves together and stop and check the progress regularly. You only want to remove about 70% of the bluing inside the rings. If you go too far the potential is there to make it so your rings can't tighten down on the scope.

Even the best made scope mounts in the world cannot overcome the variations in the straightness of the reciever, screw holes, or variations in the scope bases IMO. The exception being Burris Signature rings with nylon inserts and Dednutz mounts.

May 7, 2008, 05:58 AM
I like the lapping bar that nRuss Hayden sells because it has handles on each end for better lapping and control. Only use Aluminum Oxide abrasive to do the lapping. Silicon Carbide will embed in the rings and mar the scope tube.