The Complete Guide to Mounting a Rifle Scope
Mounting your own scope matters. A rushed mount done by someone behind a counter can cost you a once-in-a-lifetime shot. When you mount it yourself—and do it right—you know the hardware is aligned, torqued, and ready. If accuracy problems show up later, you can rule out the mount and troubleshoot faster. This guide walks you through the process step by step so you can mount with confidence.
Before you start, clear the rifle. Magazine out. Chamber checked. No ammo on the bench.
Step #1: Get the Right Tools. Don’t Skip This Step (Seriously)
If you do not have the proper tools, stop and get them. Guessing torque or eyeballing level is how mounts slip, tubes crush, and zeros wander.
Minimum kit:
• Quality inch-pound torque wrench (scope ring and base screws have specific specs; over-torque can crush tubes or strip screws)
• Level set (matched bubble levels or a purpose-built scope levelling kit)
• Gun stabiliser (vice, sled, bipod plus rear bags, or a solid improvised cradle that will not move)
• Correct driver bits for your screws (Torx, Allen, flat)
• Degreaser and clean cloths
• Blue, non-permanent thread locker (optional for base screws; see ring note below)
Having the right tools saves time and protects your optic investment.
Step #2: Pick Your Scope Mounting Hardware
You need to choose how the scope attaches to the rifle. Two main routes:
1. Base and ring setup
Traditional two-piece or one-piece base with separate rings that screw into the base. Lightweight hunting builds often use integrated lightweight alloy ring/base combos. They keep weight down and sit low over the bore.
2. Rail and ring setup
A one-piece Picatinny or similar rail bolts to the action. Separate rings clamp anywhere along the rail. More flexibility in ring spacing and eye relief. Favoured by long-range and tactical shooters. Slight weight penalty, but modern alloy rails are reasonably light.
Whichever route you choose, match ring size to the scope tube (1 inch, 30 mm, 34 mm, etc.) and choose a ring height that clears the objective bell while keeping a good cheek weld.
Step #3: Stabilize Your Gun
A steady rifle is critical. Use a purpose-built gun vice if you have one. If not, clamp padded blocks in a bench vice, use a sled, or build a stable rest from bags and blocks. Front and rear must be supported so the rifle will not shift while you work.
Level matters. Get the rifle roughly parallel to the ground before you begin; it will make later levelling steps easier.
Step #4: Mount Your Bases or the Bottom Piece/Half of Your Rings
For a rail:
• Lightly oil the underside of the rail to prevent corrosion (keep oil off screw threads).
• Set the rail in place and install screws finger tight.
• Apply blue thread locker (optional but recommended) to base screws.
• Torque to manufacturer spec with your torque wrench.
For a ring/base combo:
• Install only the lower halves so you have a flat reference surface for levelling.
• Torque base screws to spec.
• If using high quality precision rings, lapping is usually unnecessary. Cheap or misaligned rings may benefit from lapping, but good rings save the hassle.
Check that the spacing will accommodate your scope tube and eye relief range before moving on.
Step #5: Level Your Rifle Scope
Levelling lines everything up so vertical turret travel actually tracks vertical and does not drift left or right at distance.
One reliable method:
1. Attach a barrel-clamp level to the barrel. Snug but not final yet.
2. Place a small reference level on the rail, base, or exposed lower rings (whichever surface is square to the action).
3. Adjust the rifle until the reference level is centred.
4. Now micro-adjust the barrel-clamp level so it matches the reference. Your barrel level is now indexed to the rifle—do not bump it.
5. Set the scope in the lower rings. Install top halves loosely so the scope can slide and rotate with light resistance.
6. Adjust eye relief (details below) while the screws are loose.
7. With eye relief set, place the reference level on the flat turret (remove the cap if needed) and rotate the scope until the turret level matches the barrel-clamp level.
8. Tighten ring screws in a cross or zig-zag pattern ½ turn at a time, alternating screws to keep even gap spacing. Watch the level as you tighten—scopes can twist under clamp pressure.
9. Torque to the ring manufacturer’s inch-pound spec. Do not guess.
Important: Do not use thread locker on ring screws unless the manufacturer says to. Wet threads change torque values and can over-clamp the tube.
Other Leveling Options
If you run a rail, some levelling kits sit directly on the rail under the scope—simple and fast. Another method is levelling off the action raceway, though action machining tolerances vary and may not be perfectly true.
Some shooters hang a plumb line downrange and rotate the scope until the vertical crosshair tracks the string. Works well outdoors; just be mindful of mirage and wind sway.
Use the method you trust and can repeat.
Step #5: Adjust the Reticle Focus
Numbering quirk in the original sequence, but this is the next step after the scope is mounted and level.
Reticle dioptre (ocular focus) affects how sharp the crosshair appears to your eye. Set it correctly once and forget it.
How to set it:
• Turn the scope to a mid magnification.
• Point at a plain light surface (wall, sky, blank target) so your eye is not trying to focus on detail.
• Close your eyes. Shoulder the rifle naturally. Open and look at the reticle.
• If it is not instantly crisp, adjust the ocular focus ring or fast-focus eyepiece slightly. Repeat until the reticle snaps sharp the moment you open your eye.
• Verify again at max magnification.
A properly focused reticle reduces eye strain and speeds sight acquisition.
Concluding Thoughts
Mounting a rifle scope is not complicated; it just rewards patience and correct tools. Level the rifle. Match rings to the tube. Set proper eye relief. Torque to spec. Confirm reticle focus. Once you’ve done a couple, the whole process is quick, repeatable, and reliable.
If you ever see wandering zero, crushed tubes, uneven gaps in rings, or canted reticles, redo the mount. Knowing your scope is properly installed removes a massive variable from accuracy work and long-range shooting.
Ready to zero? Hit the range, confirm torque after your first few shots, and record your settings.