Hi,

While he is finally going to implement the image processing (and expect he is also going to publish the whole project :) ),

I think you don't need to bullet proof the xy IR beam matrix.

You can place the IR LEDs and Sensor arrays 2 each about 3 feet away from the target, and each IR array intersecting at 90deg. exactly at the bull's eye.

A shooter who is going to shoot 3 foot off target would be a real Bastard then.

Happy Shooting

Simon