I shot an elk this year with a Partition (180 gr 308, 2700 fps, 75 yds), and it weighed 93.5 gr. when I recovered it!!! I can't say it didn't do its job, but I don't think I'll use them anymore. You might want to check out the Barnes triple shocks. They are awesome for weight retention and nearly perfect mushrooming.
Good luck with it!