Next cannon shoot is scheduled for April 5 and I'm gettin' my cannon prepped for the event. Learned a lot last time and *this* time I'm going to have a sighting widget mounted on it so I can get a little closer to one of the 'designated' targets, heh. Have been noodling on this problem a bit and am now building a really silly looking thing that may or may not work. I'm using 1/4" steel pipe to make a sighting tube, but to spare my neck and back I've put a kink in it; i.e. I've welded two pieces at right angles, then sawed the back of the joint open. I've tried putting a first surface mirror on this opening and, sure enough, I can see around the corner. Pretty funky tho and would like to know of what others have done. Any takers?