45 and chonograph

[emptyhead]

Hi again guys . I just recieved a chronograph for Xmas and was checking some loads. The .22's, .38's,.357's 9mm's all read where i thought they would but I could not get a reading on my 45 auto loads. They would read between 130 and 150 fps for 200 grain cast and about the same for 230 tc from lee, 45 gi ball loads come in anywhere from 250 to 480 fps also same with fiocci. Any thoughts. Also i managed to shoot one of the rods at the end of the shooting session. It flew out and was bent what's a good subsitute for the rods so I wont break the eyes the next time it happens.

[BD]

Imediately replace the metal rods with wood dowels. They'll snap of clean without busting up the chrony. I have no idea why .45 acp loads would read differently than the others. If it's a Chrony brand you do need to make sure that it's opened all the way flat.
BD

[Nueces]

I had been getting too many 'error' codes on my new CED chronograph, until I moved the screens further away from the muzzle (as the manual suggested!). No more problems, other than needing extra care to line up the shots. :-D

It's a hoot to see what your loads really do, isn't it?

Mark

[Single Shot]

If you are not using the sky screens, you can use drinking straws as rods.

This only works without the screens because of strength. With screens, I use dowel rods.

[Single Shot]

I have an F1 master chrony.

If you are not using the sky screens, you can use drinking straws as rods.

This only works without the screens because of strength. With screens, I use dowel rods.

[fecmech]

I believe you are too close to the screens and the muzzle blast is triggering one of your screens instead of the bullet. With the .45 or any handgun for that matter 10' to the start screen from the muzzle should eliminate your problem.

[emptyhead]

I moved the chony about 15 ft away.

[pa_guns]

Hi

The 45 acp is a relatively slow bullet. It also is a low pressure round. This results in a fairly dirty burn compared to most centerfire loads. It's pretty likely that the cloud from the powder it getting to your screens ahead of the bullet. The answer as previously mentioned is to move the screens.

Bob

[454PB]

Another thing I've learned over many years and many chronographs is that big boolits don't need to be very close to the skyscreens vertically. If they are 4" or so above the sensors, they read better. Always sight along the edge of the barrel to be sure you're high enough. This is especially important when using a scope.

[emptyhead]

Thanks guys for the hints. This board is a wealth of knowegde. Have a happy new year

[pa_guns]

Hi

There is one other possibility. Chrono's are sensitive to light source. I have had trouble with big bullets catching the sun early in their track. Cardboard taped to the screens took care of that problem.

Bob

[Clark]

I shot my first three chrono's with handguns.
I am on my fourth, and I am only shooting rifles over it, until I want a data point on handguns bad enough to sacrifice another chrono.

The first two were Shooting Chronys from Canada.
The second two were Pro Chronos from China.

The second two are much better at triggering.
I still have to get sky over them and far enough away from the muzzle gas, but they always trigger now.