I suspect...and this is just a suspicion based off of the one gun that I received, is that these MIGHT be factory blemishes. The gun I received had about 6-8 TINY blemishes in the nitron finish. It looks like maybe a few dust particles were on the gun when it was finished and prevented the nitron from adhering to the frame....but I only noticed them a few weeks after I picked it up, and then only because I was making a very anal inspection in bright light. Since its a SS gun, and the spots were so small as to be barely visible with the naked eye, who knows, and frankly, i don't really care about a few tiny cosmetic finish issues on a shooter.