I know how the A2 flip aperture works in conjunction with the range dial as on a full A2 sight unit.

But, if one is using this flip on a BUIS with no range dial, or on an A1 upper, how does one battlesight zero it?

Are both apertures on the same plane, or do you have to set two battlesight zero ranges, one for each aperture?

I still don't understand.

What I mean is, since the apertures on the A2 sit at different heights, does it or doesn't it work like the A1, which has one aperture for 0-300m, and one for 300-500m.

In other words, is the large aperture for lower range shooting, and the smaller for more distant shots?

This is my first AR and I am going to the range to zero the irons and cowitness an eotech later today (and can't wait to get there). I am confused about the irons as well. I want to use the IBZ 50 yard method, but once the sight is zeroed, how do you adjust for elevation? The ARMS 40 A2 that I have has only windage and no elevation for bullet drop compensation at longer distances. Everything that I read always refers to zeroing and then using elevation adjustments past 250-300 meters (as in the removable handle A2 sights that came on the rifle).

Sorry about asking this ?, I am sure this has been asked many times, but having to wait a minute between searches is driving me nuts!

Aside from the Larue rear BUIS that has an A2 aperture, I was condidering switching out the A1 aperture on my Bushy C-7 16" upper and putting in an A2 flip.

Is this a wise move, condidering the fact that a using a carbine and shooting past 300 meters with irons is not likely?

Thanks Tweak!