A “Blem” is short for a blemished receiver. Blemishes are defects in the final finish of the receiver. They vary in size, position, and type.
There are three types of blems we have found in the past:
The first type of blem is missing finish. These are normally about 0.7mm or smaller in size. Usually, our Nikon does not focus well enough for us to show this type of blem. These show up as small bright spot.
The second type of blem is caused during the polishing process before finish. These show up as a roughness or depression in the finish surface. These are usually just a single small spot.
Finally the last type of blem is a change in reflectivity in the finish. We call them “tilt-a-light” blems. The finish is all present, but for reasons unknown to us, it has a “spot”.
Sometimes blems are easy to spot, and sometimes they're almost unnoticeable. Please read our feedback on Gunbroker.com, which shows that many customers cannot find the blemish.
In any case all blems are 100% functional and blemishes are purely cosmetic.