Sighting in AR-15; a 101 tutorial

[Glockguy19]

A question for you AR guys. I bought one recently and I am shooting with a friend tomorrow morning. I have put about 200 rounds through the gun and it is a blast to shoot. Since then i bought an aimpoint micro and have a question about sighting it in. During the first trip I was shooting mainly at 50 yards with the irons.

In regards to the trajectory of the bullet (1:7 twist barrel) should I sight the rifle in from 50 or 100 yards? What I mean is obviously the bullet rises then falls. Should I pick a yardage based on what part of the journey the bullet is on?

I see myself using the rifle sub 300 yards most of the time. So if I sight in the aimpoint at 100 yards. Does that mean I have to aim higher if i am shooting out to 200 yards? And lower if shooting at 50 yards? Maybe I am over thinking this based on the short distances I will be shooting. I did some searching and couldn't find much on the topic.


Thanks for input, and as you can tell I'm a rook.

 

[FPrice]

How to sight in an AR-15 is the subject of many discussions. One of the first questions concerns how far you normally expect to shoot. Since you say you will probably be shooting at ranges less than 300 yards, the Improved Battsight Zero developed by Chuck Santose may be something you want to consider. You can find it at:

http://grburnett.us/guns/ImprovedBattlesightZero.pdf

added: If you can find a copy of the October 2008 SWAT magazine, it contains an excellent article on the various zeros used by our armed forces.

http://www.swatmag.com/issues/view/october_2008

 

[Glockguy19]

Thanks for the link ill check them out.

 

[Jwpeaston]

I sighted mine in at 25 meters with the standard military 25 meter target. The target simulates a human size target at 300 meters. I have to hold a little low at 100 yards to hit my 10" gong dead nuts. I have shot out to 200 yards with this setup with no problems. Keep in mind this sight-in is for a human size target not for shooting moa groups at long ranges.

Jim

 

[glide]

25/300

You can guesstimate in between.

 

[That Guy]

The margin of error is much less if you do your zero at 100 meters if you can accurately zero at 100m (which many people cannot with iron sights). Which is why sighting it in at 25 or 50 may make more sense unless you are a fantastic shot already.

 

[ninjatarian]

The 60/200 yard zero seems to be a pretty good one and is the LE standard in many departments, keeps your groups tight anywhere from 0-260 yards. 25 yard zeros will give you a lot more variation from 0-300 and I would only use it if I knew I would be shooting to 300+ yards regularly. If you aren't shooting past 250 yards the 25 yard zero is silly

[video]http://m.youtube.com/watch?v=Klvve0ZG_jo[/video]

EOTech/AimPoint/etc Zero: A study on the effect of zero range selection - AR15.Com Archive