Although I use a 6MM-06 as opposed to a 243, I've killed a bunch of Mule Deer, a few Whitetail, Antelope, Caribou and Sheep with the 100 grain Partition with perfect satisfaction.
I KNOW that a Partition will open up and retain weight. I don't trust copper bullets to ALWAYS do that.
I tried Barnes bullets --- they produced poor groups, fouled terribly and velocity suffered ---- Oh yeah I forgot, they've got those cute rings around them now
