This is a shareware ballistics program I just found online that has some pretty cool features. It's a basic ballistics program, but also has a kind of shooting simulation built in.

You can choose between a few reticle types, change the scope magnification, dial windage and elevation, choose your target size, shape, and range, and then fire theoretical groups, with or without environmental and velocity variables.

I checked it's output against 2 other ballistics programs, and while not exactly in line with those, it wasn't too far off either.

If nothing else it's good for determining what a target of X size looks at at X range through a scope of X magnification.

Modern Ballistics