Mounting
How to Mount a Riflescope
Quick answer
Mounting a riflescope is a sequence, not one step: degrease the base, torque it to spec, check ring alignment, set eye relief by shouldering the rifle, level the reticle to the rifle, then torque ring screws in a cross pattern using a tool like the Fix It Sticks All-In-One Torque Driver Kit, 15 to 65 inch-lbs, with T-Way Wrench at $139.95.
A scope mount fails in ways that are invisible until the rifle recoils a few hundred times, which is exactly why the sequence matters more than any single step in it. Skip the degreasing and a base screw backs out under recoil. Skip levelling and every dialled correction quietly steals a little windage from your elevation. Skip torque and the tube either creeps or gets pinched, and both look identical from the shooter's chair: a scope that will not hold zero.
This guide is the whole sequence in order, the way it actually has to happen rather than the way a box of parts suggests. It assumes bases and rings, which covers the large majority of bolt actions. A flat top receiver taking a one piece cantilever mount skips the base step but everything else applies unchanged.
How to mount a riflescope
- Clear the rifle. Open the action and visually and physically confirm the chamber is empty and the magazine is removed or empty. Leave the action open for the entire job. Nothing in this sequence requires a loaded rifle, and there is no point in the process where that changes.
- Degrease the base and the receiver rail. Wipe both mating surfaces with a solvent that leaves no residue. Oil under a base screw acts as a lubricant on threads that are supposed to bite, and it is the single most common reason a properly torqued base screw still backs out.
- Fit and torque the base. Set the base or bases on the receiver, start every screw by hand, and torque them in a cross pattern in at least two stages, roughly half the final figure and then the full figure, rather than driving one screw fully home before moving to the next. Use the base maker's published torque figure. When one piece is unpublished, a common range for base screws is 40 to 65 inch pounds, and that is a starting range to confirm against your specific base, not a substitute for it.
- Set the rings on loosely and check alignment. Set the ring bottoms in place and snug the ring caps just enough to hold them, not to clamp them. Lay a set of alignment bars or a straight rod across both rings. If the bars do not seat flush in both rings at once, the ring bores are not pointing at the same place and lapping will remove the high spots. This step catches the single largest cause of a bent, preloaded scope tube before the scope is anywhere near the rifle.
- Lap the rings if the alignment check shows contact only on one side. Coat a lapping bar with compound, seat it in the rings, and work it back and forth under light pressure until contact marks show evenly across both ring bores. Wipe every trace of compound out before the scope tube goes anywhere near the rings. A kit such as the Wheeler Scope Ring Alignment and Lapping Kit, 30mm at $59.99 covers 30mm rings; a 34mm version exists for the larger tube.
- Set the scope in the rings and close the top halves just enough to hold it. The scope should be able to slide fore and aft and rotate in the rings with light hand pressure. This is not the final position. It only needs to stay put while you check the next two things.
- Set eye relief in the position you actually shoot from. Shoulder the rifle from field or bench position, whichever you actually use, with your eyes closed. Open your eyes and check whether the full field of view is there with no black ring at the edge. Slide the scope fore or aft and repeat until the correct picture appears the instant you shoulder the rifle, not after you hunt for it. Eye relief measured on a bench with a rifle rested does not match eye relief from field positions, so check it in the position that matters.
- Level the reticle to the rifle. Reference a machined flat, such as the top of the turret housing or a receiver rail, rather than the reticle itself, and square it to a level rifle held in a vise or a v-block. A dedicated tool such as the Wheeler Engineering Level-Level-Level Mounting Tool with Magnetic Base at $19.99 does this by clamping to those machined surfaces instead of eyeballing the crosshair against the horizon. See the full levelling guide for why this distinction is the whole job.
- Torque the ring screws evenly in stages. Working in a cross pattern across all ring screws, tighten in at least two passes to the ring maker's published figure, commonly 15 to 25 inch pounds. Check that the gap between the ring halves stays even on both sides as you go. An uneven gap at final torque means the tube is being pulled off centre rather than clamped square.
- Recheck level and eye relief one more time. Torquing can shift the scope slightly. Shoulder the rifle again with eyes closed and check the picture, and recheck the reticle against the machined reference. Fix anything that moved before you consider the mount finished.
- Bore sight and then zero on a live range. A bore sighter or a bolt-out look through the bore gets the first shots on paper. It is not a zero. Confirm the actual zero only on a supervised range or a safe, legal backstop, and know what lies beyond the target before firing.
What torque figure should each screw actually get?
Two different sets of screws, two different jobs, and neither number is a guess if the maker publishes it.
Ring screws typically run 15 to 25 inch pounds and base screws typically run higher, around 40 to 65 inch pounds, but the specific maker figure always governs over any general range.
Shooter convention
| Fastener | Typical range | Note |
|---|---|---|
| Ring screws (cap to base) | 15 to 25 in-lb | Clamps the tube; the ring maker publishes the exact figure |
| Base to receiver screws | 40 to 65 in-lb | Higher because there is no tube to protect underneath |
| One piece mount to receiver | 25 to 45 in-lb | Varies more by mount design than base screws do |
| Action screws (if disturbed) | Per receiver maker | Outside the scope of a mounting job but easy to loosen by accident while working nearby |
Treat every figure here as a starting range to confirm, never as a substitute for the number stamped on the box or published on the maker site.
Why the sequence matters more than any single step
Every step in this sequence exists to prevent one specific, invisible failure. Degreasing prevents a base screw from backing out under recoil. Alignment and lapping prevent a bent tube that preloads the erector assembly. Eye relief set from your real shooting position prevents a scope that gives you a black ring exactly when you need the picture fastest. Levelling against a machined flat, not the crosshair, prevents dialled elevation from stealing windage. Staged, even torque prevents both creep and a pinched tube.
Do them out of order and each one can undo the step before it. Torque the rings fully before checking level, and you now have to loosen and redo the torque to fix the cant. Set eye relief before levelling, and the small rotation needed to square the reticle can shift the picture enough to need rechecking. The order in this guide is the order that avoids redoing work.
Sources
- Ring and base manufacturer published torque specifications
- Owner-review consensus on mounting sequence and common failure modes
Frequently asked questions
What tools do I actually need to mount a scope?
A screwdriver or bit set matched to the screw heads, a torque wrench or limiter set to the published figures, a reticle levelling tool that references a machined surface, and alignment bars to check the rings before the scope goes in. A combo kit such as the Wheeler Scope Mounting Combo Kit with FAT Wrench, Alignment and Lapping Bars bundles most of this into one case, which is the simpler route for a first mounting job.
Do I need to lap my scope rings every time?
No. Lap them only when the alignment bar check shows the bars do not seat flush in both rings at once, which means the ring bores are not pointing at the same place. Many rings, especially a matched and lapped pair from the factory, pass the check without any lapping needed. Checking first is quick and free; lapping unnecessarily is not.
How do I know if my eye relief is correct?
Shoulder the rifle from the position you actually shoot from, eyes closed, then open your eyes. A full, clear field of view with no dark ring at the edges means eye relief is correct. If you have to shift your head to find the picture, slide the scope in the rings and recheck. Do this from field position, not just from a bench rest.
Can I mount a scope without a torque wrench?
You can, but you are guessing at exactly the number that decides whether the scope holds zero. Ring screws typically need 15 to 25 inch pounds, which is far less force than it feels like by hand. A fixed torque limiter costs little and removes the guess permanently, which is cheaper than remounting a scope that crept or a tube that got pinched.
Does the order of bases, rings and leveling actually matter?
Yes. Fitting the base first, then loosely setting rings to check alignment before final torque, then setting eye relief, then levelling against a machined flat, then torquing in stages, avoids redoing earlier steps. Torquing rings fully before checking level, for example, means loosening and retorquing to fix any cant, which is extra handling of screws that should only be set once.
What ring height should I buy before I start?
Whatever clears your scope objective bell by roughly an eighth of an inch, and no more, since taller rings than necessary lift your cheek off the stock. Measure the objective outside diameter and check it against the base height you are using. The ring height calculator on this site turns those two numbers into a specific recommendation rather than a guess from a ring height name.
Researched, not professional advice. This page is compiled from published manufacturer specifications, published optical and ballistic formulas, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are shooter convention rather than sourced numbers, and they are labelled that way wherever they appear. Ballistic figures come from a point mass model using the ballistic coefficient the maker publishes, so treat them as a starting point and confirm them on paper at a measured distance. Confirm your firearm is unloaded with the action open before you mount, level, torque or bore sight anything. Verify a zero only on a supervised range or a safe, legal backstop, know what lies beyond your target, and follow the law where you hunt and shoot, including rules on land access and permitted cartridges.