This short guide teaches long range shooters how to fix a canted reticle before heading to the range.
It's for better zero repeatability, better accuracy and prevent bad training scars while using a poorly set up rifle.
Canted Reticle Problems
- Errors in wind hold
- Errors in clicks & estimation (especially on a Christmas Tree reticle)
- Missed shots, Wasted ammo
- Causes shooter confusion
- Reticle subtensions are off further away from the center
- Leaving bad training scars using a bad setup that can be avoided
Things That Causes Reticle Cant
- Poor optic to mount surface contact
- Damaged scope tube / erector assembly due to previous over torquing (You will never even know it's there)
- Left / right handed shooters may position the rifle slightly canted without noticing
- Leveling the scope based off the turret surface (Inaccurate and we explain in the FAQ section below)
Do The Following To Fix Reticle Cant
1: Plum Bob
The plum bob technique is the best for mounting a scope at home. This technique eliminates the use of scope leveling tool that are inherently inaccurate when placed on top of a scope turret.
Instead, a weight attached on a string hanging dead straight down by gravity, and it's backed against a wall to give the most vertical reference straight line free from any external physical contact.
Next, allow the scope to freely rotate on the mount for micro adjustments (Use a rifle zeroing stand to make it easier)
Next, shine a flashlight towards the front objective lens and light beam will project the upside down image of the reticle onto the wall.
Finally, Re-adjust and center the reticle to the reference line as much as possible and tighten the screws slowly to the correct spec without accidently rolling the scope around the axis.
Pro Tip: Keep the flashlight on to monitor any scope rotation relative to the straight line when tightening down the mount screws. Just don't make it roll!
2: Upgrade To A Better Scope Mount
Browse Through Our Guide Here: Best Scope Mounts & Rings
If you're currently using a generic scope mount, then this is the right time to inspect and troubleshoot your setup and consider an upgrade.
The quality of the scope mount or scope ring matters a lot. A poor / inconsistent scope to mount surface contact will add tolerance error to the system, which lead to alignment offset.
A highly precision machined scope mount like the One-piece Geissele Super Precision Mount can hold on to the scope with full surface contact
For scope rings, ensure proper scope lapping is performed for the best alignment and surface contact before torquing down the screws.
Follow scope mount torque specs here
3: Professional Scope Tracking Test
The best way is to pass it to a professional that can perform a scope tracking test and see it on a collimator to ensure all turret clicks are accurate.
Is The Traditional Leveling Method Still Accurate?
Leveling a scope with a spirit level sitting on top of the turret is not the most accurate method.
The reason is because there are multiple part layers stacking on top of each other from the erector tube all the way up to the turret, which we can't assume they are as accurate as the internal of the scope.
When Is Scope Cant Actually Useful?
Referenced Magpul Dynamics
Some long range precision shooters actually intentionally cant the scope to compensate any cheek weld and butt stock placement cant since every shooter gets behind the rifle is different.
A left handed shooter positions the rifle slightly differently than the right handed shooter.