sighting in a new AR

[glockmaster]

Hi need help or tips sighting in my new S&W M&P 15. I've searched youtube but my rifle does not have the "z" to the right of the elevation dial. I took it to the range today and was shooting a little down and to the left. I tinkered with the front sight, but kept the back at the 6/3 mark and some minor adjustments with windage. Was just using my range bag as prop so hard to tell what is shooter error or the rifle. This is at 25 yards by the way. What do I need to do to be dead on bullseye???

[Philadelphia]

Hi need help or tips sighting in my new S&W M&P 15. I've searched youtube but my rifle does not have the "z" to the right of the elevation dial. I took it to the range today and was shooting a little down and to the left. I tinkered with the front sight, but kept the back at the 6/3 mark and some minor adjustments with windage. Was just using my range bag as prop so hard to tell what is shooter error or the rifle. This is at 25 yards by the way. What do I need to do to be dead on bullseye???

Do you have a distance in mind that you want to zero for? I get the sense that you want to zero for a "proper" distance (say 100 yds) but do it at 25 yds?

Also, don't lose track of the fact that AR sights are well above the barrel and that at shorter distances it has to hit low. If you zero at 25 yds to hit dead on you will be aiming for the moon at distance.

[27hand]

See if anything in this thread helps regarding holdover.
Although the thread deals with an optic, the holdover or zero point would be about the same as open sights.

http://forum.pafoa.org/optics-46/121...-m4-sight.html

http://www.calguns.net/calgunforum/s...d.php?t=162723

[ReconLdr]

Do you have a distance in mind that you want to zero for? I get the sense that you want to zero for a "proper" distance (say 100 yds) but do it at 25 yds?

Also, don't lose track of the fact that AR sights are well above the barrel and that at shorter distances it has to hit low. If you zero at 25 yds to hit dead on you will be aiming for the moon at distance.

The Army zeros at 25m to hit POA=POI at 300m. At any range in between the impact of the round will never be more than 3" or so from the POI.

I don't have access to my ballistic calculator on this computer but would estimate 25yd zero would put you 1-1.5" high at 100. I will run the numbers later but I would bet I am pretty close.

ETA: The AR platform is designed to use the front sight adjustment for zero and the rear sight for doping.

[david1]

Good post so far. I just put my first ar (bushmaster) on layaway and cant wait to get enough money for it to come home with me.

[Philadelphia]

The Army zeros at 25m to hit POA=POI at 300m. At any range in between the impact of the round will never be more than 3" or so from the POI.

I don't have access to my ballistic calculator on this computer but would estimate 25yd zero would put you 1-1.5" high at 100. I will run the numbers later but I would bet I am pretty close.

ETA: The AR platform is designed to use the front sight adjustment for zero and the rear sight for doping.

I understand what you're saying but it's a little more than three inches. With M855 and 300 yd. zero, apogee is about 6" to 8" high at roughly 175 yds. M193 is a little flatter but only a couple inches. At 100 yds out it's about 4" high for M855 and 2.5" high for M193. I did imagine it much higher in my head. Not quite the moon but on the high side.

[Xringshooter]

First, download TM9-1005-319-10, the M16/M4 operator’s manual. IIRC you can get it several places such as AR15.com. Then go here:

www.ar15zeroing.com

This document is an analysis of three different procedures depending on your goals.