Wow, I wouldn't have expected that much of a velocity. I've used both of those sabots, and find myself switching back and forth depending on the load/bullet combo. In general I've gotten better accuracy with the Harvestors at higher velocities, and better accuracy with the MMP's with moderate powder charges, but that's not a hard and fast rule. They both load about the same for me. I like to keep both on hand to try out with different loads. I've not noticed a difference when shooting in different temps, though I've never shot in temps above 60 degrees.