By sandbagging your gun, you will find out where it shoots. Ive never really cared where my gun shoots, but where I shoot my gun. lol
What I do when patterning my gun is take a large piece of paper (butcher paper, wrapping paper), draw about a 4 inch circle in the middle of it, color it in, step back about 20 yards and bring the gun up to my shoulder and fire 5 rounds at the circle.
Then I go and find the center of impact, take a pen with a piece of string attached and draw a circle around it. Compare that to my point of aim..
My pattern shows me the "thick cheek" theory I mentioned earlier. As far as height, thats about where I want it, as I like to see my target, not cover it.