Extremely low chrono readings

[Rich 10mm]

So I have a Caldwell Ballistics Chronograph that’s been giving me more off readings. Just loaded up some 10mm 180gr on top of 10.5 blue dot. Headed to the range with some test loads and got some readings of 90-130 FPS. Obviously these are incorrect. I also had some 1200-1250FPS that are about what I was loading for. I had more low readings than the “correct”. It was placed about 5-7 yards from my shooting position. Maybe it was to close and muzzle blast was giving me problems? It’s about 30 degrees outside where I’m shooting. Any help would be appreciated.

 

[kcofohio]

Battery getting low, along with the cooler weather?

 

[WrongHanded]

5 to 7 yards should be more than enough distance to avoid issues from muzzle blast. I set my chrono up at 10 to 12 Feet.

Direct sunlight has caused me issues in the past. Once, I turned the unit sideways on the tripod to avoid sunlight hitting the light sensors. It worked well.

Is it possible that at the distance you're shooting, you aren't getting shots over the sensors in the same place every time?

ETA: If the wind was blowing the unit around, that might have caused some issues.

 

[jmr40]

In addition to low batteries the amount and angle of the light matters. Also the recommended distance is about 10 feet. 5-7 yards is 15-21 feet. You may be too far away.

 

[drband]

Using sky screens?
Weather conditions?
Fresh batteries?

 

[Rich 10mm]

Fresh batteries. I got better readings when I shot slightly towards the left side of the unit

 

[jmorris]

If you can pick an overcast day and go try it out. No screens are needed just turn it on and shoot over it, like this.



If it works fine it was the ambient light messing things up. Next time you are in full sun angle it so direct sunlight isn’t hitting the sensors so the bullets can be silhouetted against the screens.