I bought this at a gun show a decade ago and forgot about it. This was a run of "NM" National Match G21 barrels that Olympic Arms had made. Stainless steel with land and groove rifling. Being over 5" it is legal for hunting in many states. Or thread it, port it, whatever. It is .2" longer than a G41 barrel, but I do not know if the G41 has the same locking profile as the G21. It probably is the same and this will work fine. On the side of the barrel there are some light pits. Apparently the barrels had gotten wet on the outside at one point and they bead blasted them clean. That's what those marks are - not casting voids. Bore is perfect. I'll sell locally or ship.