Okay, I don't know squat about tactical rifles. Took me and google a while just to figure out what BUIS stands for. Anyhow, I got these MI folding sights with my XCR, and I've gotta say they're pretty. Very high quality. Only problem is that when I put the top of the post on the bullseye at 25yds, I shoot about 5-6in low. Could be worse. You oughta see me shoot handgun. Still, a little closer would be nice. It looks to me like the front MI sight has a spring-loaded gizmo that'll somehow allow me to lower the post. Sounds better than grinding it, though I might have to sooner or later. Finally, here's the question: How do I adjust the MI front sight? Thanks.