The shape of the barrel extension itself isn't all that bad, but I also see what looks like rust inside of the extension, with some stains around barrel itself. I'd be wondering if some sort of chemical or salt water or whatever came into contact with it. What do the barrel threads look like under the extension? No way of knowing without pulling it. If they gave you to option to send it back, that's what I'd do.
Maybe I'm just a little overly cautious with this sort of thing. I saw some weird forms of corrosion after Katrina. I sure as heck dont store guns in cases with foam inserts anymore.
