Box Test
A verification drill where you dial a square pattern and shoot each corner to confirm the scope tracks accurately and returns to zero.
In a box test the shooter fires a group from a confirmed zero, then dials a set amount of elevation and shoots again, adds windage and shoots, removes the elevation and shoots, and finally removes the windage to land back at the start. Plotting the four corners on paper should produce a clean square whose final group sits right on top of the first. The exercise checks both the accuracy of the turret-tracking and the consistency of the clicks in every direction.
The test catches two distinct faults at once. Crooked or undersized corners reveal that the turrets are not moving the impact by the values you dial, while a final group that fails to land on the original point signals an unreliable return-to-zero. Running a box test on a new scope, before relying on it at distance, is a cheap insurance policy against a mount or mechanism that cannot be trusted.