Well, I now chrono every shot when I'm working up pet loads (now that I found a buddy with a Chrono
). And even though I haven't been able to do so for every gun I own here's what I found this spring when working up loads for my 7mm-08 and my buddy's 7mm RUM (this is an extreme case you'll note). But of the three powders we tried in each caliber, I was able to get all three to have and extreme spread of 25 fps or less(one even got to an ES of 14 fps), and I might add all three were among the best performing loads in my gun (not by that much mind you but we only shoot at 200 yards when working up loads). In his 7mm RUM we only found one powder that would get us below the 25 fps ES, and that only got to 23 fps ES. Now keep in mind that both of these guns with the better handloads were shooting sub-moa @ 200 yards, but it seemed to us that both guns seemed to shoot better with the more consistent loads. Now, another thing I noticed was that we tended to get the most consistent burn rate with less than max loads in both rounds. This next spring I intend to play around with this a little bit more, because it is something that we just started working with, and I really want to see if it plays out with my 300 WSM and 257 Roberts. This is just one experiment so it is possible that the results are merely coincidence, but a lot of BR shooters that I talk to seem to agree with what I've found so far, in addition it could be due entirely to the quality of powder available for the super-capacity cases vs the smaller cases, of that I'm not sure, just reporting what I've found.
Gordon