I agree about moving the chrony back. The powder and smoke can play havoc with the photo eyes. One word of caution though, be aware of the sabot and what it's doing, I had one hit the second eye enclosure and it knocked a chunk of plastic out of it at 5 yards. If you have the display on the front of your chrony you will want to protect it somehow (thick plexiglass or a brick) so an errant sabot doesn't break the display. Good luck.