Hey guys....I've been doing alot of AR shooting lately (new RRA flat-top in the family).

I took my Springfield Champion to the range with me today to shoot a box through it after I got done with the AR, and almost every single round went right.  Not high or low, just right.  Shooting at 7 yards at a circular target w/ a 4 inch diameter red "bullseye", I put all but one of 50 rounds to the right of the red by about 2 or 3 inches.  The shots were all in the same area (i.e. there was one big hole on the right side of the bullseye), but man, I couldn't hit that red circle to save my life.  What am I doing wrong?  I checked the sights, they're tight and haven't shifted, so I can't blame the gun.  I'm confused because I normally shoot much better this.

At least you are consistent....aim for the left ear when you are shooting zombies.

Probably squeezing with your right thumb or pulling the trigger instead of pressing it. Rifle shooting is far more tolerant of bad gripping habits than pistol shooting. It is possible to develop bad habits by only shooting a rifle for a while. I shoot my carry gun every time I go to the range.

Quoted: Probably squeezing with your right thumb or pulling the trigger instead of pressing it. Rifle shooting is far more tolerant of bad gripping habits than pistol shooting. It is possible to develop bad habits by only shooting a rifle for a while. I shoot my carry gun every time I go to the range.

+1
You could also be using too much trigger finger (squeezing the trigger with the first knuckle, instead of the pad of your finger). Try dry-firing it some, and try to keep the muzzle still as you squeeze the trigger. This'll save you a ton of money on ammo.

I keep shooting to the left so i feel your pain. Heres something that might help....

www.tackdriver.com/pix0703/correction.jpg

Assuming that you are right handed, you probably use too much trigger finger. Shoot with the left hand next time and if you hit to the left, it is your trigger finger/pull. Get a longer trigger or adjust the finger. Lock your wrist, too.
If you still shoot to the right, shoot from a rest to confirm that it's the sights.

I had the same problem for a little while and I just worked on my trigger control and it went away.  I don't know for sure why I was shooting that way but better trigger control fixed it.