Yeah, this is the only Glock that I've noticed these marks on as well. That's what concerned me initially. Anyone out there notice similar issues on theirs? Glock USA mentioned the same thing, BTW... to twist the frame (with the slide removed, of course), and I didn't notice the cracks moving at all. Then again, I didn't apply any appreciable force either....I just didn't feel right about twisting the heck out of the Glock's frame,...