Today I was finishing sighting in my EOTech on my new upper and started on my irons. I shot a group and noticed that the shots were going almost off the paper near the bottom of my target (20 yards). I lowered the front sight post as low as it would go to try to raise my group, which of course it did, but not enough. I went out to 100 yards to see how much it needed to go, and my shots were still hitting probably a foot and a half below my bullseye and POA. I couldn't figure out why until I got home and took off both sights from my gun.
Turns out my GG&G A2 rear is about 1/4" lower than my Troy front sight. I can tell this because if I look straight through my GG&G, I expect to see the 3/4 circle of the Troy sort of surrond my field of view. It doesn't. My question is, why? Both are meant to be mounted on the reciever/rail. Both are brand new, no damage, nothing. It almost seems as if the Troy was meant to be mounted on a gas block instead of a rail. Both GG&G's and Troy's website state that they can allign with other mil-spec BUIS. Are my sights out of spec or am I missing something here?