After I got home, I set out to ascertain the cause of the problem. I used a laser Boresighter and marked my offset on a target. I placed the target at 10 yds (the distance of the drills) and set my rifle in a rest. While the scope was off slightly (1/2 minute) this was not enough to produce the 3"-4" shift that I was experiencing. So I shouldered my rifle and started sighting the target like I would in training. After a few minutes of experimenting the "AH HA!" moment struck me.
The optic that I use on my AR rifle is a Burris AR 332. I will do a post on WHY I chose this particular optic, but that is for another time. It is enough to know what I'm dealing with. Back on topic, when I shoot inside of 100 yds, I keep both eyes open. Due to the magnificence of the human brain I can actually see the reticle with both eyes. So I tend to focus on the reticle in my left eye when shooting right handed. Especially at close range, because the magnification slows target acquisition that close. However, what I had failed to take into account is that when using a magnified optic, your point of aim shifts when you have both eyes open. In this case the shift was nearly 4 inches to the right. Of course it would shift left when shooting support side.
Follow me so far?
If not, try this:
Make a triangle with your hands.
Next, looking through your newly formed triangle, focus on an object across the room, remember to keep both eyes open.
Now close your dominant eye. The object disappears, and if you are right eye dominant, your left eye is now looking at a spot several inches to the right of your focus object.
This is the basic idea behind point of impact, and point of aim discrepancy. After doing this little experiment, you start to understand why trainers tell you to "Aim where you want to aim, not where you want to hit." when using scoped rifles. First you have to account for your offset. (The distance between your barrel and your optic) next you need to understand what your point of aim / point of impact difference is. Now if you have a non magnified 1X optic, P.O.A. vs. P.O.I. will be very little, basically you won't notice enough to really worry about, but if you, like me use a low power optic, than this can be a significant difference up close.
As for me, in order to hit in the center of the scoring zone of a VTAC target I had to aim just inside the shoulder. Which is working well, and has been consistent. And that's what it all boils down to right? You can overcome anything as long as you are consistent.
So in the end I solved my little mystery, and am now putting rounds right where I want to. I just have to remember to aim just a little off of where I want my rounds to hit.
