What is considered good accuracy from an AR? I have a Rem R15 w/22" barrel. With the best factory ammo I've found so far it shoots about 1/2 MOA. Is that what I should expect ? Or better? I have not shot it too much at any long range. I did dial with an estimated velocity and kill a possum at 366 yards the other day with one shot which I thought was good. Anyways, it's my first AR, just trying to find out what is good, average, and terrible for one.