How to Mount a Rifle Scope

By: Team ZWRR

Step 1: Choosing Proper Base & Rings

1. Use a scope base chart such as the one found here (http://www.weaveroptics.com/mountcharts/) along with your rifle manufacture and model to determine the model of scope bases needed for your rifle.
a. I prefer to use Weaver bases and rings since they have been in the industry for a long time, have a sound reputation, and are reasonably priced for the quality product they produce.

2. Select a set of scope rings to pair with your bases and scope based on the diameter of the tube of your scope. Modern scopes should have a tube diameter of either 30mm or 1 inch. It’s important to note, that since Weaver is an industry leader in the manufacturing of scope bases, alternative brand scope ring manufacturers’ do produce rings which are designed to work in conjunction with Weaver-style bases as long as the rings you purchase are marked as such.

Step 2: Mounting Base and Lower Rings to Rifle

1. Using a small-thin flathead screw driver (such as one available in the Brownells-Magna Tip Super Set shown in picture (1)) and the hardware included with your bases to mount the scope bases to threaded holes in the receiver of your rifle (usually for two piece mounts “hardware” includes the two bases and four screws). (see picture (2) for reference).

Step 3: Mounting Base and Lower Rings to Rifle

2. Mount the lower half of the scope ring to base using a larger flathead screwdriver since the smaller screwdriver (used to mount the bases) will likely slip inside the head of the screw which is used to fasten the scope ring to the base.

a. Be sure that the extrusion on the underside of the scope ring lines up with the slot in the scope base. It is important to securely fasten the large screw to the base so that the lower half of the scope ring will not move later. (see picture (3) for reference)

Step 4: Mounting Scope and Top Rings

1. Once both the front and rear lower rings have been secured to the base, set the scope into the top of the lower ring. Be sure the scope is mounted on the middle of the scope and not along the slant of the objectives.

2. Carefully spread the top half of the ring as you slide it (in the direction shown) over the top of the scope so it is not to damage the scope. (see picture (4) for reference)

3. Slide the top half of the ring forward, and over the lower half of the ring.

4. Fasten the screws so they are “snug” but not so tight that the scope cannot freely turn within the rings or slide forward and backwards within the rings.

a.  It is also important to note at this step, that if the rifle you are mounting this scope to produces a large amount of recoil that you need to have eye relief so that you do not get a case of “scope-eye” upon firing the rifle (see step 5).

Step 5: Mounting Scope and Top Rings

5. This is an optional step, applicable only if you need to ensure you have proper eye relief for your scope. Mounting the rifle to your shoulder as though you are about to fire the gun, noting the relation of the rear of the scope to your eye.

a. If this distance is less than approximately 4 inches, then it would be a good idea to slide the scope forward within the rings as much as possible to get 4 inches of eye relief.

b.  If this is not possible to do without sliding the scope rings onto the slants of the objectives, then you need to be sure that when firing the gun you slide your head back on the butt-stock of the rifle before firing the gun.

Step 6: Leveling the Scope

6. Using a Wheeler Engineering Crosshair Leveling kit, like the one shown in Picture (5). Insert rifle level as shown in the sub picture of Picture (5). Be sure that the rifle is level by making sure the bubble is in the middle of the two lines on the level, as shown in Picture (6).

7. Place the scope level on top of the scope (find a flat surface such as the adjustment caps).

Step 7: Leveling the Scope

8. Slowly turn the scope until the level bubble on top of the scope is halfway along the line that is closest to the screws as shown in Picture (7).

a. This is done because as the scope ring screws are tightened the scope will have a tendency to rotate in the direction that the scope rings tighten (toward the screws) Note that the level in the rifles action is still level (arrow).

9. Tighten screws until the scope is level; if at first you don’t succeed, then loosen the screws and rotate the scope to adjust for the turning of the scope during the ring tightening.

10. Visually confirm that the crosshairs are level by mounting the rifle and looking through the scope. See Picture (8).

Step 8: Sighting in Rifle Scope

Now that the scope is mounted, it’s time to site in the rifle!

Step 9: Range Preparation

1. Select a large target, usually one with multiple aiming points; and a box of ammunition.

a.  It is important to be consistent with the ammo which you will use to sight in the rifle because each variation of ammunition will vary in how it fires through the rifle and thusly will impact the target at different locations. See Picture (9) for reference.

Step 10: Range Preparation

2. Before taking to the range, remember the “The 10 Commandments of Firearms Safety”. Found here for your reference: http://www.remington.com/~/link.aspx?_id=5B6EB408A13E4DE5960FD674D7459CAC&_z=z 

3. Following commandment 4 (be sure of your target and what’s behind it) look at the dirt berm for a backstop; also note that while there are steel target on the berm none of them are behind the target (see Picture (10)). Set the target at 25 yards and find a solid resting spot such as a truck hood, as seen in Picture (11).

Step 11: Clear the Barrel

1. Since your rifle is likely new, it is important to shoot a few rounds off paper to eliminate any oil or other residue that could be in your barrel. Be sure that the fired bullets will land safely in your backstop before pulling the trigger. Such as to the left of the target, or just above the target in Picture (10).

Step 12: Shooting Target

1. Now that your barrel has been cleared of any fouling

a.  Aim for the center of the large target and fire three shots.

i.  When I aim I like to line up the crosshairs in the scope with the yellow lines you can see extending from the target (both vertically and horizontally) in order to find the center properly.

ii. Be sure to use proper technique when firing the rifle, squeezing the trigger as you line up on the target and ensuring that the rifle is firmly mounted in your shoulder pocket.

2. Clear the firing line

3. Walk down range to examine where you hit the target.

a. As an alternative you could bring a spotting scope or a set of binoculars to help spot where you stuck the target in order to adjust your rifle.

Step 13: Analyzing the Target and Making Adjustments

1. As you can see in Picture (12), my shots were seven inches right and four inches high. Therefore, the scope needs to be adjusted 4 inches down and seven inches to the left (@ 100 yards).

a. Since we are firing from only 25 yards away, the 100 yard adjustments need to be magnified out to 100 yard. For this scope, the adjustments were quarter inch per click at one hundred yards. Since we are at 25 yards, four times the 100 yards adjustments were necessary. It’s important to note that each riflescope adjusts differently so you’ll have to examine your specific scope.

2. Now that you have made adjustments, it’s time to try again.

Step 14: Analyzing the Target and Making Adjustments

a. Fire three more shots aiming at the same large center target, and repeat adjustments as necessary until all three shots are soundly on paper (See Picture (13)).

i. If your shots are not “grouping” well than you probably need to focus on controlling your breathing, and squeezing the trigger.

[I’m no expert shooter, but my shots weren’t grouping because on this particular day the conditions were a little breezy, but for the purpose of this Instructable I decided to sight in anyways

Step 15: Different Distance

1. Move back to 100 yards.

2. Again use steady support, since this time I am firing from a bench and not from the hood of a truck, and am firing from a farther distance I am using a front adjustable bag and rear heavy bag as shown in Picture (14).

a. Again, aim for the large center target and fire a group of 3-5 shots, as shown in Picture (15).

3. Spot the impact location of the group you just fired and adjust your scope using the 100 yard adjustments on your scope as seen in Picture (16).

a. As I said earlier, breezy conditions strung out this group, but all shots are within the paper plate size circle (which is approximately the size of a White-Tailed deer’s vital organs).