I have one "10mm" mag. Not sure if it was manufacture specifically for 10mm, or a 45ACP modified (although 45 rounds do not stack neatly in the mag...but 10mm do). The front of the mag is clearly stamped "Auto-Ordnance Corp, Bridgeport..." There are no other markings on the mag. Nowhere is it labeled "10mm". I will also tell you, the rifle has a feed issue. Just about every other round I get FTF. Not sure if that is caused by the mag, or (more likely) the flat nose 10mm round getting caught on the edge of the feed-ramp. As you all know a lot more about this weapon than I, maybe you can help solve the problem Requested pics attached. Let me know if ya need anything more Cheers!