gutpile11
I am always afraid of hitting the chrono with a sabot - so I set mine really close to the muzzle, about 12 feet on a steady tri-pod (2 legs to the back one leg at the muzzle). The blast from the barrel will deposit some material on the chrono, the rods that hold the sky screens and the screens themselves...
I protect the chrono - it is totally wrapped in turkey basting tin foil - the thicker stuff. I then cut away the foil over the sensors and apply clear package tape across them. The face is protected with a heavier clear piece of plastic (like a thick zip lock bag) taped in place.
The problem: after shooting it is necessary to wipe the equipment down with a damp cloth + oil the sky screen rods.
So far I have been really lucky - I just betting the sabot can not come off in 10-12 yards....