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Posted: 12/24/2010 4:30:27 AM EDT
| Alright, so I need a rear BUIS and don't need it to be detachable. I am considering a DD BUIS, but I am not sure how the A2 rear aperture works on the sight. Is this going to shift my POI when I flip apertures (small to large)? If so, could you explain anything I need to know? Thanks! |
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A2 apertures are not same plane:
http://www.thehighroad.org/showthread.php?s=d12ed884b93d31f78c23671462acd203&t=154455 Q: What is the change of impact between the two apertures in the A2 sight? A: Courtesy of XS Sights from their website (http://www.aosights.com/news.html FAQ #10) ...Comparing some of the rear sights available today there appears to be 3 variations available. The 1st style (and oldest) has a .014 offset. This gives a 2.52 inch shift in point of impact at 100 yards between the two apertures. The 2nd style has a .017 offset, which shifts point of impact 3.06 inches at 100 yards. The 3rd style has a .024 offset giving a 4.36 inch shift in P.O.I. All of the points of impact shifts shown above are for the standard barrel AR-15/M-16 that has a sight radius of 20 inches. The shorter sight radius (14.5 inches) of the M4 carbine and weapons of similar configuration increase the amount of point of impact shift. The shifts for these shorter sight radius weapons are 3.48, 4.25, 5.96 inches respectively.... However, the DD sight is a "A1.5" so I'd shoot DD an email and ask them directly. |
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