Sorry to hijack the thread, but my experience with DPMS isn't exactly great. I bought a collapsable buttstock assembly from them, and when I screwed the tube in, I discovered the threads weren't CNC'd. In order to get it to hold the detente down, the tube had to be screwed in enough so that the collapsable stock was at about a 10 degree angle off center. I tried it on multiple lowers, and had the same result. I ended up taking it back to the dealer, and they traded me even for a Bushmaster kit, which had a timing lip on the tube to address that issue.
"Democracy is two wolves and one sheep voting on what to have for dinner.
Liberty is the well-armed lamb contesting the vote." - Benjamin Franklin