First, I have searched and found endless threads about how to zero a rifle and 50/200 vs 25/300 battle zeros, but nothing about using the other positions.  I do realize that 300 yards is already a long shot for an iron sight carbine, but I want to know if the range markings on an A2 style elevation drum work correctly with the carbine sight radius on a weapon like a 727 or XM4?
Thanks

It has been a while since I browsed this thread but I think what you seek is in it.
http://www.ar15.com/forums/t_3_18/328143_.html

Thanks but that whole article (which I've read before) is explaining the different zeroing schemes and doesn't address my question.  

There was one part however where the author mentions the elevation difference between the large and small apertures causing an issue on carbines.  Because the carbine's sight radius is so much shorter the elevation difference becomes drastic.  That's the same principal as my question.  If on your 20" A2 you twist from the 8/3 mark to the 5 mark you should increase your elevation by a certain angle which puts you on target at 500.  Now same scenario but with a 727 instead of an A2 rifle.  The front and rear sights are much closer together so when you twist from 8/3 to 5 you're adding a much greater angle of elevation than you did with the rifle.  Won't you shoot too high at 500?

I do realize the carbine produces less muzzle velocity, so maybe that evens it back out?

Thanks

I think the differences were minimal between the carbine and the rifle that it was easier to have the same equipment across the board for both rifle and carbine. And yes you're right the velocity difference between rifle and carbine does tend to compensate for the shorter sight radius.

I don't think iron sights on the M16 were meant for extreme precision, more like minute of commie. Hitting Ivan an inch too high at 500m was not even in the equation...because I mean come on....you hit Ivan at 500m.... you're the man!

I think the A2 8/3 elevation wheel was a bit overly optimistic. Perhaps it was meant for massed area fire by a platoon or some such.  Kind of like the 1000+ meter leaf sights on old military bolt actions.

The 6/3 flat top elevation wheels are a bit more realistic...but even then 600m on a 5.56 is really pushing it. Your velocity is really dropping at that point.