Sounds like you have bottom metal offer. If the muzzle diameter is all you need my ctr barrel measures .785 inch just in front of the oem foreend. I’m sure theres several folks here who can measure other points on the barrel if needed.What’s the muzzle diameter? It’s not so much the barrel fitting but the bottom metal that comes on the ctr. If someone wants to send us the factory ctr bottom metal we could do a program for it.