Don,
I asked about the equipment you were measuring MV with, because some chronograph brands and models have better reputations than others. Now I'm not pooh poohing your chronograph just for personal enjoyment, but that chronograph doesn't have a stellar reputation for producing accurate and repeatable velocity measurements.
When I review your load #2 chronograph data and see an extreme spread (delta) of 238.7fps, and an SD of 102.8, I'm further convinced that your chronograph reported some bogus velocity data. I would totally dismiss the load 2 velocity data.
I wouldn't spend much time analyzing the rest of your velocity data in any detailed, serious manner, solely based on the model chronograph you're using. You also obtained a fairly large delta for load 3 (but nowhere near as extreme as load 2).
Beyond that, I will note that load 1 used WLRM primers and loads 2 & 3 used Fed 215M primers. Even if all other components, powder charges, and aspects of your loaded cartridges were identical, the use of different primers often yields different MVs. So that adds another variable, in addition to the use of the unfired and once fired Nosler cases. If you wanted to explore the affect that once fired cases versus virgin brass has on MV, you would really want to keep all other aspects of the loaded cartridges identical. Powder lots, seating depths, primers, powder charges, case and case neck preparation - everything else should be kept as constant as possible.
Hope you get your elk!
