Tune_up
Member
How do you use your chronograph data. I’m not interested in setup and function, but what value do you get from the measurements and how do you use them to work up loads. I realize that with an average velocity you can calculated bullet drop at various ranges, but what else?
How accurate are chronographs, my ProChrono states at least +/- 1%. Measuring a 3300 fps .223 bullet that’s a 66 fps spread on identical velocities. Yesterday I shot two 10 shot strings on different loads. The first averaged 3300 fps, an extreme spread of 40, and a standard deviation of 14. The second averaged 3021, extreme spread of 90 and Standard deviation of 34. Other than the average velocity, can the other measurements be considered significant? Whats the most likely cause of velocity variation? load? powder? case volume? crimp? my loading technique? ect?
How accurate are chronographs, my ProChrono states at least +/- 1%. Measuring a 3300 fps .223 bullet that’s a 66 fps spread on identical velocities. Yesterday I shot two 10 shot strings on different loads. The first averaged 3300 fps, an extreme spread of 40, and a standard deviation of 14. The second averaged 3021, extreme spread of 90 and Standard deviation of 34. Other than the average velocity, can the other measurements be considered significant? Whats the most likely cause of velocity variation? load? powder? case volume? crimp? my loading technique? ect?