Why Lap Scope Rings?

Lapping—or truing up the inside surface of your scope rings—protects the outside of the scope tube from damage; eliminates stress on the tube that could affect the integrity of the scope's internal moving parts; and aids accuracy by removing any stresses that the scope tube could be applying to your rifle's action.

Is lapping scope rings really necessary?

When using some designs of scope mounts, lapping is recommended to get the best performance. Lapping can increase the amount of surface contact between the ring and scope tube, and also help with proper alignment between the scope rings.

What does lapping rings mean?

To oversimplify, lapping simple means “sanding” the interior of the ring to obtain a perfectly smooth and precisely shaped surface. ... Using a perfectly shaped steel rod, one grinds and smooths the rings using a lapping compound until the rings are ground ever so slightly into the perfect shape.