[Cow Town Bill]

On the weekend I got the opportunity to compare my Labradar with my brand new Caldwell (free replacement for a defective one). I used my 22 PPC with 50 grain Hornady Vmax bullets and H322 powder.
Five shots using the Labradar got an average velocity of 3497 fps and a SD of 13.6.
Next 5 shots using the Caldwell gave an average of 3535fps and SD of 19.5. Another 5 shot group gave an average of 3515 fps and SD of 14.2.
Net result is that both chronographs agree fairly closely. If I get some spare time at the range I'll set up so I can measure the two chronies simultaneously.
I took these readings on a beautiful blue sky day. However, as the sun began to set behind me the cargo trailer that I shoot from cast a shadow on the chrony---then I got some bad readings from the Caldwell even though the unit was looking up to a clear blue sky. It seems that the combination of sitting in a shadow looking up to blue skies can give readings as much as 150 fps higher than other readings.
One reader suggested blacking the bullets and I may try that. Conclusion is that the Caldwell can work under ideal conditions. I use my Labradar under almost any conditions and get good results. The only drawback to the Labradar is the velocity limit of about 3700 fps---that's when I will use the Caldwell (under ideal conditions).