I have the ProChrono Digital (the same one that Grouse has pictured in the homemade box). I used it for the first time a couple weeks ago with my M/L. I set it on a tripod @ 10 ft. from the muzzle. The only protection I used on it was a piece of 1/8" thick plexiglass, cut into approximately a 5 1/2" square. I took a single piece of duct tape and taped the top of the plexiglass square to the top front of the ProChrono and it hung straight down in front of the keyboard/display. If a sabot had hit it, the plexiglass would have swung back and inch or so until it contacted the housing of the chronograph and the sabot would have been deflected harmlessly to the ground. I used Dead Center and Shockwave sabots and Triple7 powder and had no problems whatsoever with a sabot hitting anything. The sabots were found downrange several yards from the chronograph. I shot 35 shots through it and the ProChrono didn't even have a trace of fouling on it. Overall, I was very pleased with the performance of it, plus the plexiglass shield on the front of it gives me peace of mind while shooting sabots through it.