Not a comparison of those two but with other X-bullets. It seems that some at higher velocity end up with the petals laid back on the shank of the bullet based on wound channels and a very few recovered bullets. Once it does this it acts more like a wad cutter bullet.

I suspect that at more moderate velocities the interval when the petals are in "full flower" is longer. That the slower bullets have a slightly longer interval at maximum diameter. Purely speculative but I believe there was some high speed photography done by Barnes in clear ballistic gelatin that could support this theory.

WDM Bell also thought that bullet rotation was a factor in lethality. This is what he attributed the effectiveness of the Swift on Red Stag at longer ranges after velocity had dropped off. Some of the military testing would tend to support this as well.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli