Scope Mounting – Easy and Simple

As shooters many of us like to tinker with our guns. Mounting a scope correctly is one of those skills every shade-tree gunsmith should learn. With a few tools, a little patience, and attention to detail mounting your own optics is simple and easy.

Scope mounting is no more complicated than making sure your scope reticle is level and square to the rifle and the screws are properly tightened.

Tools of the Trade

Proper gunsmith driver bits
Image by Randy Bauman

Start with good tools. If you are going to own and maintain firearms a set of gunsmith screwdrivers or bits is your first investment. Screwdrivers that fit are critical to ensure you do not damage the screw heads on your guns and optics mounting systems.

Be sure your tools include bits for both Allen head screws as well as Torx screws.

Next, invest in a Fat Wrench. The Fat Wrench is made for gunsmithing chores. It is perfect for applying the proper torque to rings, bases and action screws. If screws are properly torqued it is very rare for them to loosen over time.

fat wrench for mounting a scope
Image by Randy Bauman

A dial caliper can be handy, but is not absolutely necessary.

A set of bubble levels helps to determine if the rifle receiver and the scope are level.

levels for mounting a scope on a rifle
Image by Randy Bauman

You will need a tube of Loctite. Get the blue stuff. You want to be sure your screws stay tight, but you also want to be able to remove those screws at a later date. Just a little drop on the threads is all it takes.

It helps to have a gun vise or some way of securing the gun and keeping it level while you work on it. If you don’t have a vise or cradle, just use the sandbags you use at the range to help keep your rifle secure.

Finally, you will need some rubbing alcohol and cleaning patches to remove all solvents and lubricants from the receiver, the bases, and the rings before you start mounting your scope.

Mounting the Scope

Proper tools for mounting a scope
Image by Randy Bauman

Step 1

Gather all your tools as well as your bases, rings and scope.

Step 2 

Be absolutely certain your gun is unloaded and there is no ammunition in the area while you are working on the gun. It is amazing to me how many times we hear about a gun going off when someone is cleaning it or working on it.

Unload the gun, remove the magazine and remove the bolt. Now double check it. Firearms safety is your responsibility.

Step 3

Use the rubbing alcohol and cleaning patches to clean the bases and rings as well as the top of the rifle receiver. Be sure to clean the screws and screw holes.

mounting holes for a scope
Image by Randy Bauman

You want to remove all traces of lubricants or solvents before mounting the scope. A microscopic layer of oil will prevent the bases and rings from being fully tightened and will allow the mounting components to move ever so slightly.

Step 4

Do a dry fit on the bases and lower rings. Do not tighten anything yet or apply any Loctite. Your are simply checking to be sure the parts fit properly and that you have the parts assembled in the correct order.

Depending on your firearm, you may have front and rear rings that are different heights. Now is the time to get them in the correct place. Not after you have started tightening screws.

Step 5

Once the lower half of the rings are positioned on the bases, gently place the scope in the rings. Check the spacing between the rings and the turret housing as well as the front objective bell and the rear ocular bell. You will likely need a bit of space to adjust the scope fore and aft to establish the proper eye relief.

rifle scope
Image by Randy Bauman

Your rings may be able to be reversed to provide ample adjustment. If you need more space, flip the rings around and check your spacing again.

Step 6

If you are satisfied with your dry fit assembly, take all the components apart and lay them out in the order you will do the final assembly.

Step 7

Mount the bases. Check the recommended torque settings for the base screws in the mounting instructions. If you don’t find a setting, jump on the manufacturer’s website to look up the torque values.

Set your Fat Wrench for the proper torque and insert the correct bit for the screws. Place a dot of Loctite on each screw, then attach the bases to the receiver. Alternate between screws as you tighten them so the base mates up squarely to the receiver. Finally, use the Fat Wrench to apply the proper torque to each screw.

Step 8

Attach the lower rings to the bases. Again, check the torque values for this step and tighten the screws as directed.

Step 9

Place the scope in the lower rings and the upper rings over the scope. With no Loctite on the ring screws, attach the upper rings just enough to hold the scope, but loose enough so that it can be turned to level the reticle.

Step 10

Shoulder the rifle as if you were going to shoot offhand. With a natural cheek weld and good hold, check to be sure the eye relief is correct.

You should see a full bright view through the scope. If the there is just a circle in the middle or your you see a fuzzy black edge, move the scope forward and backward until the full view is seen.

Shoulder the rifle several times to ensure the adjustment is correct. If you close your eyes, shoulder the rifle, then open your eyes, your view through the scope should be full and clear.

If you have to adjust your eye or head, move the scope and try again. This takes some time, but get it right so every time you pick up your rifle your view of the target is perfect.

Step 11

Level the rifle using one of the bubble levels. This can be done by placing a level on the receiver, it if is flat or your are using a rail mounting system.

level used to mount a scope
Image by Randy Bauman

You can also use your dial caliper to create a flat surface across the bottom of the magazine well and place the level on the flat of the caliper. Some levels are designed to fit in the bolt raceway to allow you to level the rifle.

level used on a scope mounting
Image by Randy Bauman

Once the rifle is level, place your other level on the elevation turret cap of the scope. Turn the scope as needed to level it. If the scope does not have a flat turret top or cap, you can hang a string, like a plumb bob, in front of the gun to provide a perfectly vertical reference to align the reticle.

Step 12

Tighten the rings. When the rifle and scope are level and the eye relief is properly adjusted it is time to tighten and torque the scope rings.

The rings will have at least two screws each and maybe as many as six depending on the design. Be sure to give each screw a dab of Loctite before you begin tightening them down.

Alternate between screws and tighten in a sequence that allows the ring to move straight down over the scope tube.

Keep an eye on the gap between the bottom ring and the top ring and try to keep the space on each side even as you tighten the rings. Once all the screws are torqued you are finished.

Step 13

Bore sight the scope. Bore sighting is nothing more than aligning the scope reticle to the center of the rifle bore. Place a target that you can see well at 100 yards. Set up the rifle on a solid rest and remove the bolt. While looking through the barrel align the target to the center of the barrel.

100 yard target bore sighting
Image by Randy Bauman

Now, without moving the gun look through the scope. You want the scope aligned on the center of the target. If needed, adjust the elevation and windage turrets to bring the reticle to the center of the target. Check the bore alignment to be sure the rifle has not moved as you make adjustments.

When the bore and scope are both aligned you can now be confident that your first shots will be on the target.

Step 14

Zero the scope. When the bore sighting is complete you can now fine tune the zero firing three shot groups. Be sure you know how much the adjustment clicks will move the point of impact at 100 yards.

Once your scope is zeroed you are ready to head to the field for hunting, continued load evaluation, or reaching out to targets at longer ranges.

Final Thoughts

Invest in good tools. The tools will last a lifetime and you will find yourself helping your shooting buddies mount their optics once they know you have the skills.

Take your time. It takes awhile to get things level and adjusted properly. It’s not a race. Do each step correctly and you can be proud of having a properly mounted optic on your rifle.

Have fun. Guns are supposed to be fun to own and shoot. Learning to do some of your own work gives you a sense of pride and accomplishment every time you hit the range with a gun you have worked on yourself.

Any questions or concerns? Leave a comment below!

Easy and Simple scope mounting


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