Well, I finally got a new Eotech rail riser on my AR-15 flat top.
Everything is all mounted, using blue Loc-Tite on the rail mounting screw.
The rail is not absolutely perfectly centered (left to right) on the flat top. The front iron sight and the Eotech reticle are not vertically aligned. Yuk!
I'm going to shoot it some, and see if minor adjustments are appropriate. Otherwise, I guess it will have to be broken down and recentered.
Probably shoud have taken it to a gunsmith.