It's the Predator!
That's probably a good thing, if you want to use the circle to see where the pattern is going to be. The trick is making sure that the laser spreads the same as the shot. You'd need to change filters when you change chokes, too.It would actually be VERY easy to make a circular patterned laser sight. It would be like one of those laser pointers that draws a symbol.
The problem is, the spread. Once you run a holographic filter, the circle would get bigger as the range increases....which wouldnt work to well for shooting.