Properly Mount and Level your ACE Thermal Scope

If you're mounting a thermal optic—especially one with a round tube design like the ACE—you can't afford to eyeball it. Unlike traditional day scopes, many thermal optics don’t offer a clear, visible reticle when powered off, which makes traditional leveling methods unreliable. That’s where a scope leveling wedge becomes an indispensable tool in your setup kit.

What Is a Scope Leveling Wedge?

A scope leveling wedge is a simple but incredibly effective device that helps ensure your optic is square and level to your rifle’s rail. The wedge slides into the space between the flat bottom of the optic’s housing and the top of the rail or mount. As you gently press the wedge in, it creates even pressure and alignment, forcing the scope into perfect parallel with the mounting surface.

Nocpix factory mount shown with an adjustable torque wrench and scope leveling wedge. 

Why Leveling Matters—Especially at Distance

When a scope isn’t level, the consequences show up downrange. At shorter distances, you might not notice much of a difference. But stretch your shots beyond 100 yards, and the effects become significant. Instead of just vertical bullet drop, you'll start to see left or right drift—because your crosshair isn’t in true alignment with your bore axis. That deviation can throw off your accuracy, especially when you’re compensating for elevation or using ballistic calculators.

The Thermal Optic Challenge

With traditional scopes, leveling often involves using the reticle—lining it up with a plumb line or a bubble level to ensure the crosshair is vertical. But with thermal optics, that’s not an option. Thermal scopes don’t display a reticle until they are powered on, and they can’t see really see the bubble inside a glass bubble level, and creating a thermally visible plumb line is likely a lot more effort than just using a simple wedge tool. A leveling wedge eliminates the guesswork by relying on the physical flat bottom of the scope—not the visual cues inside it.

Round Tube Models vs. Integrated Mounts

Not all thermal scopes require this step. Models like the SLIM, which come with an integrated mount, are already square and level from the factory. But if you’re working with a round tube design like the ACE, leveling becomes a critical part of the installation process.

The ACE includes a factory 30mm mount, but it ships loosely installed to give shooters the flexibility to set proper eye relief before final torque. If you’re using this mount, remember to torque the screws to no more than 20 in-lbs (make sure you are not using an automotive tool with measurements listed in ft-lbs) to avoid damaging the optic or rings. If you’re switching to a third-party mount, always follow the ring manufacturer’s torque specifications.

Torque to the specifications of the ring/mount manufacturer. Over-torquing can strip screws and aluminum mounts.  

Final Thoughts

Using a scope leveling wedge might seem like a small step, but it can make a big difference—especially for thermal optics and long distance precision scopes. In a world where precision counts and every shot matters, proper installation is non-negotiable. Invest in the right tools, install it right the first time and make every shot count.