Now that I have my chronograph (ProChrono Digital based on info here and 5 star review on Midway's site), I am ready to take some measurements. From other threads, it looks like the preferred condition for measurement is with a "cold" barrel (i.e. letting the rifle cool down between measurements). Since it is running 100 degrees (or near enough) in Houston, "cool down" is a relative term.
Anyway, any tips on getting accurate readings (or ones that would be of interest to other board members), like how many rounds are needed to get meaningful results, how important is standard deviation, average and median speed, etc. Should I be measuring group size at the same time? I gather from other's experience I should avoid shooting the chronograph
. Should I record temperature, wind, and humidity conditions? Anything else?
Barring any input to the contrary, my plan is to heat up the barrel with 20 rounds, then shoot strings of 20 with a hot barrel, basically to compare Hornady and Remington factory loads against each other under similar conditions and my reloads against the Hornady Handbook data .