I have had a pact xp chronograph for about a year. It works very well on cloudy overcast days but when the sun comes out forget it. The l.e.d. screen reads NO START SIGNAL DETECTED. I have called pact twice , the first time they said to tilt the sensors and skyscreen to one side or the other in an effort to change the amount of light recieved by the sensors.This did not work,and imagine if you can shooting through a chrono tipped to the side, it's just not right.The next time I called the guy on the phone told me that the sensors are set at the factory for optimum conditions and that if they changed the sensors to work in bright light I would experience the same problem only now it would be on cloudy days. The sensors are set at a happy medium & thats the way it is . I have a cardboard shade which works sometimes but not reliably. Last time out,bright sun,NO START SIGNAL DETECTED,and my improvised shade did'nt work,so I picked up the tripod and moved the unit from 10 feet, and in the sun to 4 feet from the muzzle & out of the sun, in the shade of the shacks roof.The chrono worked good for the rest of the day.The chrono survived my 22-250 @4 feet, but I fear ruination with the 8mm rem mag. A fellow shooter suggested I try putting black tape over the aluminum base to reduce glare.I will try anything. Long story short;Don't buy a Pact XP.