The very BEST recommendation I can give you regarding a chronograph is DON'T SHOOT IT!! :grin:
The instructions that came with my F1 Chrony said that for optimum reading, the bullet should pass between 4" to 6" above the sensors. Taking into acount a 1 1/2" scope height, I took some black electrial tape and wrapped it around the sky screen support rods about 6 1/2" above the sensors. I took another piece of electrcal tape and put it in the center of the front sky screen.
When shooting with my vairable scope on lower magnifications, I can see all three tape markers. I line up the horizontal cross hair with the two taped marks on the support rods and lign up the vertical cross hair with the taped mark on the sky-screen.
When shooting with the scope on higher magnifications, I can NOT see the the tape markers. So, I first use the lower magnification to lign up scope with the target keeping an eye on the tape markers. I adjust the Chrony/tripod as needed and then go to the higher maginfication to shoot.
So far so good! No Shot Chorny! (Knock On Wood!)
firstshot
------------------------------------------
Make your first shot count!