Red Dot - Zero and Drop

[ExtremeX]

I got a PA Micro Dot with a high mount for the AR...

As of right now I got a zero at 25 yards (local range)

Someone please correct me if im wrong, for 5.56 55gr, I need to be hitting 2" below my dot to be zero at 100 yards?

Asside from that: What do you guys typically zero your RDS at for general purpose? 50 or 100 yards?

[esskay]

I got a PA Micro Dot with a high mount for the AR...

As of right now I got a zero at 25 yards (local range)

Someone please correct me if im wrong, for 5.56 55gr, I need to be hitting 2" below my dot to be zero at 100 yards?

Asside from that: What do you guys typically zero your RDS at for general purpose? 50 or 100 yards?

Finer points depend on your muzzle velocity, optic height over bore, environmental conditions, etc, but the last time I ran ballistics for my 16" pushing AE223 at about 2925 fps for a 100yd zero it would hit 1.6" low at 25yds.

I zero my RDS at 200yds, which is very close to a 50yd zero (but not quite). This gives a nice useful trajectory throughout that range.

[ExtremeX]

Ive been messing with the ballistics software from Federal for the XM193 round, or at least I think that's the round its selecting... It assume I am using a 24" barrel, no way to change it.

Sight over bore is about 3", 16" barrel.

I'm just trying to get get sighted in for 100 yards at an indoor range before my next desert trip.

Can anyone recommend software for making drop charts?

[esskay]

http://www.jbmballistics.com/ballistics/calculators/calculators.shtml

[HK Dave]

Red Dot zeroed at 50 yards will hit slightly high at 100 yards and almost dead on at 200 yards.

I zero all my red dots at 50 yards.

[Gatordev]

I got this from over at M4carbine.net (or maybe WEvo...I can't remember). It's not the end all answer, you still need to zero at the "real" distance, but it gets you close at a shorter range, pretty quick.