Brownells Scope Ring Lapper

Guns Magazine, Jan, 2001

Scope bodies are made of aluminum while scope rings that hold them are made of steel. Does this suggest a potential problem? As anyone who has ever installed, and then removed a scope knows, the answer is yes. The problem comes in the form of "ring dings," scratches and abrasions on the anodized aluminum scope tube.

The solution is to properly align a set of rings before installing a scope, making sure the rings are perfectly concentric and true. This is especially important with pivoting rings, like Redfield and Leupold, that are often torqued into place by the scope itself -- a very bad thing.

Enter Brownells' "Scope Ring Alignment Lap," a specialized tool for lining up a set of rings and then lapping them to remove any high spots or other manufacturing defects that can mar the surface of an aluminum scope tube. The tool consists of a precision steel rod, exactly 1" or 30mm in diameter, with two handles to enable a brisk lapping action.

The Brownells ring lap comes with lapping compound. To use, install the bottom half of the rings as normal, then insert the Brownells lap as if it were a scope. Loosely tighten the top half of the rings. Slather on a generous portion of lapping compound and begin moving the lap back and forth in a rapid fashion.

Eventually you will see the compound turning grayish, indicating the lapping action is removing some material from the rings. Loosen the rings, remove the lap and inspect. There will be shiny spots through the bluing on the rings indicating where the lapping compound has polished out a high spot. Continue until the lap moves freely through the rings without binding.

Remove the top halves of the rings. Keep them separate! Your rings are no longer interchangeable, they're mated. Keep the orientation of the rings the same as you put them back on your scope -- left-front matches to left-front, et cetera.

Et voila, perfectly mated rings, perfectly aligned scope, no more "ring dings" on your scope. Brownells sells the scope ring lap for $34.11 (1") and $42.22 (30mm). There is enough lapping compound included to last for a lifetime supply of scopes, at least for the average guy.