Theohazard I have looked through a couple of the flip up rear sites. They are not out of the equasion. I did have a red dot on a 22 once. It worked fine. IIRC I also mounted one on my marlin 357 lever action. I used to shoot other guys handguns with red dots at the falling plate matches I used to shoot in the early 90s.
I called DPMS this morning and tried to pin down if it has an F marked front sight or the shorter sight. The guy on the other end just kept saying any carry handle will work with my gun. I asked if a Bushmaster handle would work on my gun. Same answer. He didn't offer to sell me a detachable handle so I guess they don't sell them.
I may shoot this for a while with a scope on it till I figure out what it is I want for a rear site. Anyway I am having fun here. I have also bid on a second AR.
The second gun has the fixed rear sight. So this first gun may end up with a scope after all.
Dan I will send you a PM.