They may have been cause by that. Not really sure. Gun functions fine. I did contact CZ just to get there impression. Figured I should should get the answer straight from the horses mouth. They said the marks are normal and not a problem. They did offer to take it in and have them polished out if I want to which is cool of them. Ow just need ti decide if I want to leave it or have them polished out by them. Either way I decide it was nice of them to offer even if it is only cosmetic.