I used 95 grain SST in my 6mm, which is just a bit hotter than .243. I shot 2 or 3 deer with it, I liked that non-deformable tip. What I did not like though was that it often did not exit. One particular white tail buck, I was very confident I hit it, but I could not find a drop of blood. It took me more than 30 minutes of walking around in circles before I found him, probably not 50 yards from where I shot him. When I shot him, he went right, but what I didn't see was that he circled back left behind a small rise and then fell over. The bullet had gotten his lungs and I think part of his heart and stopped just under the skin on the far side, perfectly mushroomed.
Anyway, as you well know, two holes usually bleed better than one and it can be right tricky to find a deer in the brush if he's circled around and you didn't know it. I've moved back to 100 grain Core-lokt as I've had better experience with them doing just as much damage with the addition of an exit hole.
Now, 150 grain SST out of my SX-AR .308, no problem whatsoever on deer!