You have to shoot at least 10 shots to get a clear idea of the average speed of a given load, and the more you shoot, the more accurate your idea will be. That's prohibitive for load development.
I've used the older-type versions from PACT and a couple of MagnetoSpeeds. The PACT-style units take while to set up and don't always work well on cloudy days. The MagnetoSpeed attaches to the barrel, which throws your POI, so you can't test for accuracy and speed at the same time.
I'm getting a Garmin so I can test for accuracy and velocity at the same time. I'm really interested to see what 100- and 200-shot averages look like with a couple of loads.
Okie John
How are you going to handle the temp changes??
I'll probably make notes and study how the changes correlate with the data, then ask a lot of questions on the 'fire. Fortunately, temperature swings here aren't very big and we rarely reach the extreme ends of the scale. Hunting seasons rarely get below freezing and summers rarely get above 90F.
Okie John
Cool, I'd be interested in seeing your results.
I make it a practice to get multiple chrono sets at different temps to upload into my ballistic software. Normally I just go for 10 shot strings, or for however many shots I'm practicing for. I've got some loads for a couple of my precision rigs that might have that many rounds total, but all were purposely shot at different temps.
