Here a while back, an upstanding member of our board here sold me a Troy MRF 13.8" rail at a terrific price. When I received the rail, it was brand new, still in the Troy box. I was enthralled, until I put it on that is. The receiver height didn't match up. This isn't an unfamiliar problem in the .308 AR world though, so I figured I'd have it cured in no time by simply ordering the correct height receiver. I put in a call to DPMS, who told me that the difference between their old receiver and the new is that the new one is higher. WRONG! So I ordered a new A3 upper based on what they told me. When I get it, the receiver heights are the same. I had a newer style receiver to begin with. So I place a call to Troy and explain that I have two new uppers of the wrong height and they quickly explained that if I had an older DPMS A3 receiver, the heights (between the rail and my upper) would've matched. They told me to send my upper back to DPMS for a refund. Then he told me to send him back my Troy rail, and he'd replace it with the correct height rail, don't worry about not having a receipt or anything they'll replace it. That's customer service! I may hang on to my new stripped upper though, you can never tell when it will be useful to have a spare upper!