I'm confused - zeroizing a rifle (AR)

[Guest sargekw]

When I first got my AR, the folks at the store/range helped me to sight in the Eotech holographic sight I got to go on the rifle.  The range is 25 yards long, so the sights are set for that.  The thing I am confused about is I have recently gone out twice in the past couple months to put some rounds through it, and I'm finding out I have to change my point of aim depending on the size of the target I'm shooting at.

 

​One time I was shooting at a silhouette target that was about 1/4 to 1/3 the size of a regular sized silhouette target.  I had talked to someone before that and found out that from previous times shooting that I was hitting below where I wanted to hit (1" dot) because my point of aim was too low (center of the dot).  I adjusted my point of aim to make it about 2 inches (height of optic above barrel) above the 1" dot I was trying to hit and I left a big hole where the dot used to be. 

 

Today I went to the range and this time I was shooting at a regular silhouette (skeleton) at 25 yards.  I had marked on the target where my point of aim should be based on my hits on the smaller sized target.  My first shot ended up being close to the mark I had put on the target.  I adjusted my point of aim to where I really wanted to hit and that's where the shot went.

 

This is where I'm confused - why is my point of aim different based on the size target I'm shooting at??

[Oh Shoot]

....

This is where I'm confused - why is my point of aim different based on the size target I'm shooting at??

 

It's not. Only distance matters. Has to be technique if sight is holding zero in between sessions/shots.

 

That said, with a 25 yard (actually meter) zero,  there's about 3" difference in POI from 0 to that 25 yards, and maybe your two target examples are not really both at same distance?

 

- OS

Edited October 30, 2014 by Oh Shoot

[Omega]

Shouldn't be, unless you are using a part of the target as a reference.  An interesting thing about military zero and 25 yard qual targets is that the circle in the center is the same size no matter what size the silhouette is.  Get or make same size reference circles and place them on your target and use them for reference. 

[peejman]

The bullet trajectory is pretty steep when using a 25 yd zero. This magnifies the vertical change in POI based on range.... small changes in range cause the POI to move more than they would using a 50 yd zero.

 

[Spurholder]

OP, check these out - HTH:

 

http://www.m4carbine.net/showthread.php?95226-Improved-AR15A2-A3-A4-amp-AR15-Carbine-Zero-Targets-50-200M-100M-amp-300M-Zeroes

 

And since you're running a RDO:

 

http://www.m4carbine.net/showthread.php?96955-Zero-Targets-Optimized-for-Red-Dot-Style-Optics-(Aimpoint-EOTech-etc-)

Edited October 31, 2014 by Spurholder

[Jct1911]

Go re-zero to 50yds. Holdover is almost nil at 200yds. The dot/circle reticle will make hits out to 500 with a little practice.