I would call tech service at Chrony - I just sent mine back today. Been having trouble with mine and lost confidence in it so this last weekend I set my Chrony RIGHT behind a new Oehler 35P of a friend of mine. Oehler was set at 10 feet and my Chrony at 13 feet. Shot everything from a pellet gun, 22LR, 38 spec, 357 mag. 2- 280AI and a 458 through them both at the same time. No matter how it comes back I will be ordering another chronograph and be running them back to back from now on. Really leaning towards getting a CED M2 from here at LRH but sure would like to see one operate first. No one I know is running a CED here in Billings, Mt.
I've started moving my Chronograph back to around 20 yards to eliminate the false readings. I assumed there was powder or something interfering with it. I haven't had any problems since I've moved it back.
I found readings erratic on overcast days. In sunlight, more accurate. This is because the MV reads start and stop as bullet passes thru the shadow of the screens. No shadow usually when sky is overcast.
1. no 2 chrony's will read the same
2. be consistant with distance from muzzle, 15' minimum
3. ALWAYS use sun covers/screens
4. LEVEL LEVEL LEVEL the chrony
5. muzzle brakes can wreak havoc with readings at close range
6. last,but not least, who cares about MV/ES/SD if round shoots/hits where you want it and no pressure signs ?
Your gonna have to explain #6. If I am using ballistics software I need to know that info, at least in my mind.
Let me know what I am missing.
Sorry, didn't mean to imply these numbers are unimportant. Just that I don't let them dictate what load I use. I use the chrony a lot, mainly for MV and ES, and work with a load to try and keep ES to a max of 30 fps. The SD is a nice touch, but changes to much with the number of shots fired in a string. But the factor I use most is how well the round performs at the distances I want and I test at all ranges, (up to 800 yds for me)