Just a though. When I started loading we didn't have chronographs. We figured posted velocities were about where we were and we worked up loads depending on pressure sign's we saw or felt in the bolt handle. We never had the problem, ?, your describing! Sometime's many people get in to deep with the science of the whole thing and chase it rather than dealing with what they have. Forget the chronograph and work up a good load that works in that rifle what ever it may be. Once your done chronograph the load and you know what you have! The only problem I see here is your overthinking the problem took's we have today tend to help over thinking along!If Don is referring to difference between Hornady's test rifle and ours, then yes, I agree as well. I just can't get my head around the velocities we are getting. In thirty five years of reloading I don't ever recall working a load down from minimum.