Well, fishing line and hanging from the diffusors is a bad idea. The tube swings like a pendulum, is hard to align, and unless the chrony is perfectly level, doesn't stay aligned between uses. Further, anywhere near the muzzle of the air gun, and probably even from just the pellet whizzing through, the tube is going to swing in the breeze.
So . . .
Refrigerator magnet, tape, and small wooden dowel result in the first major revision of the concept chrony bore sighter: This stays put, is wind-proof, can be easily attached or removed, and is easy to adjust if needed. I will be manufacturing these for sale, $25.00 + S&H if anyone is interested (LOL) Patent pending, etc. Should be able to tell at a glance now if I am "bore sighted" over the detectors at any distance.
PS: Pay no attention to the large chip missing from the front face of the rear detector.
TEC