How I install scopes

[AJ]

To be able to use the most accuracy your rifle can provide your optics have to be mounted correctly. Typically when I see someone at the range with a gun that won’t shoot, I assist them with remounting the scope. This many times has fixed the problem. If the scope’s tube is being pinched or stressed it will not track true (even if the scope has a gold ring).

To properly mount a scope you must be sure the rings are aligned properly when they are mounted on the receiver. There are alignment tools for this job made commercially or if you know a machinist, have them make you a set from 1” or 30mm aluminum with one of the ends turned to a point.

Install the rings with the alignment tool. Put a dab of grease on the dovetail portion of the ring (if using that type). Install the tools in the rings with pointy end facing each other. Never use the scope to turn a dovetailed ring in the mount as it can damage the scope and it’s not a warranty repair. With the front and rear ring securely installed look at the alignment tool and see if the points are pointed exactly at each other. Usually they will not be exact and occasionally there needs to be a shim added to the front or most typically to the rear mount. Remove the ring and add the shim stock under the mount not under the ring and test again. Once the points are exactly aligned it is time to install the mounts.

There is nothing worse than having a gun shoot bad groups because the screws loosened from recoil. This can be prevented by properly using a thread adhesive (Lok-Tite). Use acetone to degrease the screws and holes prior to applying adhesive. Make sure to use the proper adhesive. The blue Lok-Tite 242 is the stuff to use. If you use the red stuff 262, you will need heat to get the screws out if you decide to change, remove, etc the scope later. Apply the Lok-Tite to the mount screws and secure the mount (to include the shims) to the receiver.

I have a 1” piece of aluminum round stock that is 36 inches long. I install this in the rings and have the long end towards the muzzle. I adjust the rear ring mount until the rod is aligned perfectly with the barrel. This will usually get me on paper on the first shot. You can also use a wooden dowel as long as its straight.

Once the rings are aligned parallel to the bore, I now lap the rings to ensure there is enough contact area to hold the scope during recoil. I use a hand lap and a slurry of lube and abrasive that is made from garnet. The garnet will not imbed in the rings and cause damage to the scope. The lap is installed in the rings and the rings are tightened just to the point where the lap is hard to move. I work the lap in a figure 8 movement. You will feel the lap getting easier to move. I adjust the ring screws again to add a little more pressure and keep making the figure 8 passes. Keep this up for a while, adding more abrasive compound as needed. It will take a while to finish and your arm will feel like spaghetti, but it will be a perfect fitting job when done. You can occasionally remove the ring caps and clean the rings to examine how your progress is coming. You want about 80% or better contact area. The contact area will show up as a silver area on blued rings.

If you are not energetic enough to do that, there are other options. You can purchase or rent a scope ring reamer. This will do the job very quickly. If you are not careful, you can ruin the rings quickly also. Insert the reamer and lightly tighten the rings. Only turn the reamer in the cutting direction. Turning the reamer in the opposite direction will damage the reamer.

Once the rings are lapped or reamed, I degrease the rings with acetone and then I mix some bedding compound and put a thin skim coat in the ring bottoms and caps and insert an old scope that has been properly treated with a release agent. Be sure to use release agent on the ring screws also. I tighten the screws just barely snug using 2 fingers. I don’t want to tighten them down completely as this will not give any room to tighten the rings on the scope. Clean up the epoxy that has oozed out the sides with a cotton swab. After the epoxy has cured for 24 hours, I remove the scope and clean up the rings.

Now that we have our rings fitting perfectly to our scope, it’s time to install the scope. Once everything is aligned properly, remove the top half of the rings and install the scope. Degrease the ring screws and holes and apply adhesive. Torque the ring screws and let the gun sit over night before shooting.