Not a drop in - Faxon Firearms Smith & Wesson M&P Full-Size Flame Fluted 9mm Barrel

Not a drop in fit. 5 thousands too wide at the loaded chamber protrusion. So it wouldn't even drop in. About 4 thousands too long from locking shoulder to the back of said chamber protrusions. So if it did it would have issues and lock up. It arrived loose outside of its open factory clamshell, just getting slammed around in a plastic bag with no packing material. I'm fairly certain it was someone else's return anyway as the thread protector was screwed on the barrel, while the clamshell packaging has a little spot for it to sit separately and that's how other retailers display it in the packaging.