I have been reloading for some years, but on Friday I complimented my reloading by measuring the muzzle velocity of various loads for three separate calibers.
I shot 5-shot groups and measured different velocities for almost every shot in a 5-shot group. The biggest difference for any of the 5-shot groups between the fastest and the slowest, was 110 ft/sec and the smallest difference was 15 ft/sec. The average difference between the fastest and slowest of 15 groups that I shot, is 48.33 ft/sec.
My questions are:
1. Is this normal or will factory loads measure the same velocity for every shot in a 5-shot group?
2. If it is acceptable that the velocities in a 5 shot group will differ, is there a standard to determine what acceptable tolerances are?
3. What sort of difference in velocity will indicate a serious problem or error?
I shot a .243, a 6.5 x55 and a 30-06 (5 x 5-shot grouping with different loads for each) and for each rifle the groupings were totally acceptable.
I use an electronic scale to measure the loads and rely entirely on this scale for consistent measurements.
Thanks in advance for your advice and ideas.
I shot 5-shot groups and measured different velocities for almost every shot in a 5-shot group. The biggest difference for any of the 5-shot groups between the fastest and the slowest, was 110 ft/sec and the smallest difference was 15 ft/sec. The average difference between the fastest and slowest of 15 groups that I shot, is 48.33 ft/sec.
My questions are:
1. Is this normal or will factory loads measure the same velocity for every shot in a 5-shot group?
2. If it is acceptable that the velocities in a 5 shot group will differ, is there a standard to determine what acceptable tolerances are?
3. What sort of difference in velocity will indicate a serious problem or error?
I shot a .243, a 6.5 x55 and a 30-06 (5 x 5-shot grouping with different loads for each) and for each rifle the groupings were totally acceptable.
I use an electronic scale to measure the loads and rely entirely on this scale for consistent measurements.
Thanks in advance for your advice and ideas.
