Many gun owners like to leave scope mounting to the professional gunsmiths. However, the process isn’t all that difficult. With the right tools and know-how, you can mount your own scope without having to fork out a ton of cash to a professional. Mounting your own scope also means you can mount it right where you want it for a truly custom fit.
Before you start, be sure to read through these guidelines for proper scope mounting. We are going to walk you through the entire process, step by step. After you follow the process, you’ll want to take your new set-up to the range, so you can admire your new view.
Gather the Proper Tools
Mounting a rifle scope is a relatively simple process. You will only need a few basic tools. However, it is important that you have all the proper tools for the job.
Whatever you do, don’t improvise. Although you may find something that works, using the wrong tools could potentially damage your optic, your rifle, or both.
Collecting all the necessary tools before you start will save you time and frustration during the mounting process. Here are some things you will need.
- Screwdriver bits. (Not all mounting systems require the same bits. We recommend investing in a set of gunsmithing bits to protect your fasteners.)
- Bubble level to properly level your optic.
- Gun vise (Optional, but very handy.)
- Gun oil or rust preventive.
- Cleaning patches (Never use cotton balls. They leave fuzz that can get stuck in your equipment.)
Preparing Your Rifle
Before you start, remove the magazine from your weapon and check to make sure it is unloaded. Now is also a good time to thoroughly clean all contact surfaces, screws, rings and bases. After cleaning, wipe all surfaces dry and add a small amount of gun oil or rust preventive. (We highly recommend good old-fashioned Rem Oil. This quality product has been trusted by shooters for generations.)
Match Rings and Bases
Most modern rifles come pre-drilled and tapped for scope bases. If your scope isn’t pre-drilled, it probably has grooves so you can add appropriate mounting attachments.
Mount the Base and Rings
Always mount a scope as low as possible, making sure the objective bell doesn’t make contact with the barrel of your weapon. A scope with a large objective lense may require a high mount, but you should still mount the scope as low as you are able.
You also need to leave adequate clearance at the scope’s eyepiece to allow the bolt to function properly.
After determining the proper location for your scope, position the scope mount on the upper receiver.
(If your rifle has a free floating rail, avoid placing the mount on both the rail and upper receiver.)
Align the base with the mounting holes in the receiver. Make sure there is enough distance between the ring areas to fit the tube space on the scope.
Tighten each screw. Tighten each screw alternately, using partial turns until all the screws are tight. This will ensure an even fit. Be careful not to over tighten your screws, but you will want them tight enough to clamp securely to the base. If you over tighten your mounting screws, you could strip the thread or accidentally break your screw heads. 15-20 inch-pounds of torque is usually sufficient.
Newly manufactured rings may have burrs or rough spots left from machining. Before mounting, check your rings and lightly file away any snags if necessary. This process is called “lapping” by the professionals and improves the surface-to-surface interface between the scope and the rings.
You may want to line the inside of your rings with electrical tape to protect your scope from scratches. This also makes for a tighter fit. Be sure to trim away any excess tape with a razor blade.
In order for your scope to fit properly in the rings, the rings must be properly aligned. If the rings are not precisely aligned, it could create stress on the scope tube, potentially damaging that expensive scope.
Visually inspect the rings to make sure the edges run parallel to the scope’s tube. You can also use a scope ring alignment and lapping kit for the most precise alignment.
Before moving on, apply a small drop of thread-lock compound to your screws. (We like Loctite Heavy Duty Threadlocker Blue 242.)
Add the Scope and Align the Reticle
Position the scope on the bottom half of the rings. Then, tighten the top half of the rings, leaving enough slack for adjustment.
Make adjustments in the scope’s position for proper eye relief. This will ensure your eye is safe from recoil. Be careful. You may need more room than you think.
You also need to make sure you have a full field of view when you shoulder the rifle and look through the scope. The image should be sharp and clear when you look through the eyepiece.
Hold the rifle level and rotate the scope until the reticle (or crosshairs) is precisely vertical and horizontal. You can use your bubble levels to assist you with this step.
When the reticle is not perfectly aligned, it can cause your shots to miss right or left of the target. This problem worsens when engaging a target at distances greater than 250 yards, so if you plan to make long-distance shots, a properly aligned reticle is imperative.
Tighten the Screws
Once you are happy with the scope’s position, it is time to tighten the ring screws. To prevent scope rotation, tighten screws using only partial turns and alternating screws in an “X” pattern.
The amount of torque necessary will vary depending on your ring system. Check the manufacturer’s recommendations for best results. 15 to 25 inch-pounds of torque is a good general recommendation.
Once you have tightened the screws, look through the scope to make sure the reticle is still level. You can also use a professional reticle leveling system for the most precise results.
Before you head to the range to zero your scope, you can get a rough zero by bore sighting your rifle.
First, secure your rifle in a rifle rest or gun vise. If your rifle has a bolt action, remove the bolt so you can peer down the barrel through the receiver.
Next, center the bore on an object across the room. Being careful not to move the rifle, adjust the reticle using the elevation and windage knobs located on the top and side of the scope until the crosshairs are positioned over the same object.
Alternately, you can use a laser bore sighter. (This one from Laserlyte is our current favorite.) This method is more precise than peering through your bore and is the only way to get a rough zero for rifles that are not bolt action. Be sure to use the proper insertion pin for the caliber of your rifle. All you have to do is adjust the vertical and horizontal axes until the reticle matches your point of aim.
Bore sighting is the best way to get your rifle to print on a paper target at 50 or 100 yards without some serious guesswork and a ton of potential frustration. However, bore sighting is not the same as zeroing your rifle. You will need to shoot test groups at range to properly zero in your new scope.
Once you have your scope mounted, the next step is to hit the range. Even if you have a properly mounted scope, it doesn’t mean you can just start shooting and expect to hit your target.
To get a proper zero on your newly mounted scope, start at a relatively close range. We recommend 25 yards. If you can put lead on target at 25 yards, you should be pretty close at 100 yards. For most precision shooting applications, you can do all your fine-tuning at this range. However, some long range shooters prefer to zero their scopes at a longer distance.
No scope no matter how fancy or well-mounted, will make you a better shooter. The only way to improve your skills is to spend some time practicing. Invest some ammo and range time and you’ll be key holing bullseyes and impressing your buddies before you know it.