Nice work chaps..
From those results, on your gun (REV)
You're getting the highest velocity and smallest spread (by quite a long way) with the 4.51 die 46 pellets.
So if the theory's correct - that should be the pellet that groups best. (and also takes less wind).
An interesting thing to note from your results is that by lubing the 4.52's the average velocity went up and the shot to shot deviation improved. Even though the velocity and spread isn't as good as the unlubed 4.51's.
What that suggests to me is that - lubing the 4.52's improves things, but your barrel likes a smaller head size. The lubing thing is consistent with that - a lubed pellet potentially won't have as much scoring from the rifling.
From Arms Dealers results - it looks like lubing made things worse for the 4.52's, the 4.51's weren't as consistent downrange as your results, but the average velocity was higher than the 4.52's.
So I'd predict from those results that the 4.51's would group about the same as the unlubed 4.52's in windless conditions, but would take slightly less wind when it's blowing, so should group a little better in the wind.
Would you say those predictions tally up with your real world findings chaps?