Be real careful with your DW. I have a 445SM and from year to year and frame to frame there were some variances in the the threads. Things like threads not being cut exactly the same or true. It sounds odd but with those fine threads being what they are if you got a narrow barrel and a large receiver you could end up blowing parts off the end of the gun or it could pull out when you torque the nut. I got this info from a DW rep. But all my parts for my gun fit except a compensator nut that flew off while I was shooting. I had the comp cut off the shroud to fix it.