I got my 9mm Performance Center CORE to shoot dead center off of a sand bag. When I shoot free hand I am shooting low right, but with a tight group. After about about 150 rounds I get the same result. It clearly isn't the gun, it is me. The beauty of a red dot is that it takes a simple adjustment, if I am consistently off, to put my groups on center. Fixed Iron sights is a different story. If your gun is on center from a rest, but off center free hand, then you are left to work on your trigger control. At what point do you say enough and use Kentucky Windage?