I know what onehorse is saying but lets keep the 243 where it belongs in deer and heavy varmit hunting. Proper shot placement is always the key no matter what caliber your are using.
Just to be clear, I'm not advocating the .243 for any game even close to the size of an elk. In fact, while I was a taxidermist, a hunter brought me a black bear that he had killed with a .22, and I'd hardly call that a bear round. I think luck had a lot to do with both of these kills.
For 3212: As for wanting bullets to fragment, that's a big mistake!!! If you intentionally used bullets that would fragment so they would work for frontal shots, what happens when you get a shot that hits bone? I just don't understand the logic to this. Effective big game bullets stay together and expand. Even in the scenario you presented, it's more desirable any day to have a a dead deer on the ground (even IF the field dressing MIGHT be a little messy), than a wounded deer (with bullet fragments inside) running off and dying a slow wasted death. Fragmenting bullets are for varmints - big game animals deserve better.