OK, I have a "Chrony" chronograph. On two separate days I have used it to try and chronograph loads from my 375H&H using GS custom HV's. On both occasions, the loads have failed to register, either getting an "ERR 2" or not registering at all. My 500/416 loads chronographed fine. What am I doing wrong? Any suggestions?
Thanks, peter.

Peter
buy an Oehler model 35 or 35p.
Or wait until you have an overcast/cloudy day.

p.s. be sure your bullets are going thru the screen's detection area.

muck

I think that Err2 means that the second sensor is not seeing the bullet.

Mine acts up if the batteries are getting low.

If it's possible where you shoot, you might want to try shooting in a slightly different direction. And bring a gun that shoots cheap ammo so you can test the chronograph beforehand and not waste $1 a shot shooting the 375.

As far as why your 500/146 worked, it's likely the bigger bullet casting a bigger shadow. I don't suppose I'm telling you anything you didn't guess on that one.

H. C.

also make sure your are about 15 feet from the muzzle.
if your shooting around noon in the summer that will cause the sensor not to detect.

Other things to try,; put a piece of frosted Scotch tape over the sensor. Blacken your bullets w/ a Sharpie. Really, think about getting an Oehler before they are all gone.

I have a Chrony too and they are very finicky (ok, I plan to upgrade to an Oehler). I have been fiddling with this thing for years and this is what I have found with mine:

You must have the two sensors perfectly lined up with the bullet path.

Forget shooting in early morning or late evening with direct sunlight (also the best shooting times as the wind is typically calm). The sun comming at the chrono at an angle will give you fits.

Set the chrono 10-15 feet from the muzzle and adjust the height as close as you dare to the bullet path. (be careful with magnums - trust me )

On bright, sunny days you need a light difuser. The one that comes with the chrono is junk. Make one from recesed light difuser material or similar translucent plastic.

Ok, I just talked myself into an Oehler.

Yes, a custom diffuser may solve your problem - chronys work best on cloudy days (diffuse light).