I am trying to do a bit of research about how much the muzzle velocities of cast bullet loads vary.
I have a chronograph set up in my tunnel so I measure the velocities of a lot of loads. It is surprising how big the extreme spread in velocities are in some loads that still shoot well. Others with small spreads don't shoot so well. Nevertheless, variations in velocities can't be a good thing, especially at long range, so it would be good if we could reduce the extreme spread (ES) and standard deviation (SD) of our loads.
I would be grateful if those of you that have a chronograph would tell me the average extreme spread of your good cast bullet loads.
To keep it simple please send the ES (and SD if you have it) for ten consecutive shots. Either one ten shot string or the high and low in two five shot strings. If you answer with just the ES number please let me know the average muzzle velocity since I want to convert the ES to percentage of MV. Also please let me know the caliber (308,243, etc.)
PMs are OK but just posting it to this thread so all can see is better.
Thanks for taking the time to look this up and post it.
John