25 yard zero or 50 yard zero for Iron sight?

[hkusp9c]

I know it has been discussed several times before. But with my eye sights, I highly doubt that I'll be able to identify targets beyond 100 yards. I have a DD M4 and I'll be shooting irons only for a while. I'm going to sight it in this weekend and I need you guys' expert advice. Thanks

[Jicko]

50yds.

Assuming you are shooting M193 spec ammo @ 3150fps.

For iron sights, if you zero @ 50, anywhere from 0 to 225yds, you will hit +/- 2", that would be good enough for even a head-shot.

YDs DROP(in)
0 -2.0
25 -0.9
50 0.0 <- ZERO
75 0.6
100 1.0
125 1.1
150 0.9
175 0.4
200 -0.5
225 -1.8
250 -3.4


For optics, sight to bore say 2.5", if you zero @ 50, anywhere from 0 to about 260yds, you will hit +/- 2.5".

YDs DROP(in)
0 -2.5
25 -1.1
50 0.0 <- ZERO
75 0.9
100 1.5
125 1.9
150 1.9
175 1.6
200 1.0
225 0.0
250 -1.4
275 -3.2


Most people will use a 50yds zero, just to simplify things.

But there is a way to figure out the "optimal" zero distance for your particular rifle and load.... and your defined target (4" or 5" hit zone)..... it would come to somewhere between 35-40yds... you just want to fine tune the flight path of your bullets so that the +ve and -ve are equal and it dissect your hit zone(ie. +/- 2" or +/- 2.5"). Just use a online ballistic calculator and you can you find that out for yourself....

[aplinker]

I would recommend 50yds.

A 50yd IBZ gives you +/-2" from 50-200yds.

If you do 25yds the crossover is 300yds and you can be 5"+ off in-between.

(these are approximate values)

[NSR500]

RIBSZ 50/100

Real east to setup at a public range.

[RobT2K]

RIBSZ 50/100

Real east to setup at a public range.

+1
Best for shooting at standard shooting range distances (100/200/300/400 and beyond)
and having your POA=POI. Instead of being +/- 2"

How to:RIBSZ