To mount a scope, you set the rings on the base, place the scope loosely, slide it until you get a full sight picture, level it, and then tighten the ring screws a little at a time to the number your ring maker gives. That is the whole job. The order matters more than the tools, and the torque matters more than muscle.
This post walks through each step with the numbers the scope and ring makers publish. At the end, we cover when it makes sense to bring the rifle to us instead. Everything here is for an unloaded rifle. The NSSF’s rules of firearm safety say to keep a gun unloaded until you are ready to shoot, so check the chamber and magazine before you pick up a screwdriver.
How to Mount a Scope, Step by Step
Start with a rifle that already has a base or rail on it, and rings that fit that base and your scope tube. Then work in this order.
- Hold the rifle steady. Outdoor Life clamps the barrel in padded vise jaws or uses a solid cradle, so the rifle does not move while you work.
- Level the rifle itself. Set a bubble level on a flat part of the rail. If the rifle is tilted, your level is wrong from the start.
- Attach the rings to the base. Vortex says most rings are held at about 35 to 45 inch-pounds at the base. Check the paper that came with your rings, because makers differ.
- Set the scope in the rings, loosely. Put the scope at its highest magnification. Snug the ring screws just enough that the scope stays put but you can still turn and slide it by hand.
- Set eye relief. More on this in the next section.
- Level the reticle. Then tighten the ring screws in stages.
Do not skip step 2. The rifle is the thing everything else is measured against, so level it first.
How Do You Set Eye Relief on a Rifle Scope?
Eye relief is the distance from your eye to the scope’s rear lens that gives you a full, clear picture. Set it by feel, with the rifle at your shoulder.
You do not need a ruler. Vortex says to shoulder the rifle at the scope’s highest magnification and slide the scope forward or back until you get a full sight picture with your head in a natural position. Vortex starts at high magnification, so set that first.
Two spacing rules help while you slide the scope:
- Keep the rear ring at least 3/8 inch away from the scope’s magnification ring. Vortex warns against letting the rings butt up against it.
- Outdoor Life gives a rule of thumb of a quarter to a half inch of space between the objective bell (the big lens at the front) and the barrel.
Shoulder the rifle the way you will really shoot it. If you shoot from a bench, try the bench. If you will shoot hunting positions, try those. Then lock your position and mark where the scope sits with a pencil dot on the rail, so you can find it again.
How Do You Level the Scope Reticle?
Leveling the reticle (the crosshair) keeps your vertical line truly vertical, so the scope is not tilted in the rings.
With the rifle level in the vise, you have two common ways to check the crosshair:
- Place a small level on a flat spot on the elevation turret, with the cap off if you like. Outdoor Life describes this method. Vortex lists it as an optional step for extra accuracy.
- Hang a plumb bob (a string with a weight) at the target and line the vertical crosshair up with the string. Outdoor Life lists this too.
Keep the screws only snug while you do this. When the crosshair is straight, hold the scope still and move on to tightening.
How Tight Should Scope Rings Be?
Tighter is not better. Here is what the makers say.
| Source | Ring screws | Base or rail screws |
|---|---|---|
| Vortex | 15 to 18 inch-pounds | 35 to 45 inch-pounds at the ring-to-base connection, for most rings |
| Outdoor Life | About 20 inch-pounds | About 30 inch-pounds |
The numbers do not match, and that is normal. Rings differ by maker. Vortex itself says to always follow the recommended specs for your own scope and rings, so use the sheet in your ring box first.
A few more points:
- Use a torque wrench. Vortex recommends a quality torque wrench because it removes the guesswork.
- Tighten in a cross pattern, a little at a time. Outdoor Life compares it to tightening lug nuts on a tire. Keep the gap on each side of a ring even.
- Thread locker is a split decision. Vortex says not to use it, because it can act like a lubricant and lead you to over-torque the rings. Outdoor Life suggests one small drop of blue thread locker. Follow your ring maker.
- Too much torque does real damage. Vortex says it can permanently crimp the scope tube, and in extreme cases crush it. It can also limit dialing range and weaken zero retention.
After You Mount It: Bore Sight, Then Zero
A mounted scope is not a zeroed scope. Mounting gets the scope on the rifle. Zeroing, with live rounds, gets the crosshair and the bullet to meet at one distance.
Between those two steps sits bore sighting, a quick alignment that gets you on paper so you do not waste ammo. We cover both the visual and laser methods in our post on how to bore sight a rifle, so we will not repeat it here.
At the range, NRA Women starts at 50 yards, moves to 25 yards if you cannot hit the paper, and finishes at 100 yards. It also says to re-sight whenever you change ammunition, including brand, bullet type or weight. If you are still choosing rings, our post on scope ring height covers how high they should sit.
We do not have a range at our shop, so the live-fire step happens somewhere else.
When Is Paying $45 the Smarter Call?
You can mount a scope yourself, and many people do. It takes a level, a torque wrench, and some patience. It gets harder when you do not own a torque wrench, when the rail is crooked, or when you just bought the scope and would rather not risk crimping it.
Our posted price for an optic mount is $45, red dot or magnified, on our gunsmithing price list. If you buy the optic from us, we install it for free. Bore sighting is a separate $15. The posted prices are for a firearm in factory condition. If other changes have been made to the rifle, we look at the job first, and the price may vary. No appointment is needed. You can walk in.
The work is done in the shop, not shipped out. That means you can see the price before you hand over the rifle, which is not common in this trade.
Ready to get a scope on a rifle? Read the gunsmithing page for the whole price list, or contact us with the rifle and the scope and we will tell you the price before you drive over.
