Ticoman, I have one of those uppers but I can not tell you a lot about it, other than it works like it is supposed to. I bought it at the last Savannah gunshow from ARBunker. the barrel is made by DTI but the upper reciever and B, BC, and CH are CMT, I think. I don't know if the barrels are MP tested or not. You can get them either crome lined or not. The one I wanted was a flat top M-4, but it was not chromed, so I ended up getting a 16 inch flat top with an H-BAR, chrome lined barrel. I have only put about 200 rounds of xm193 and q3131a through it, with no problems. One of the guys I shoot with sometimes was a little familiar with DTI, he works at DD and seemed to think they were OK, at least he hadn't heard anything bad about them. Wish I could be of more help.