Because of problems with .243 diameter bullets I'd substitute a faster round for the 100 grainer you're planning. I'd try the 87 gr' spire point hunting bullet from Hornady. It's not a varmint bullet, neither is it an interloc. It's their hunting bullet, however, and it's greater velocity should help it open up better on a deer-sized animal. That's my sincere opinion -- one I'm going to try talking a very good friend of mine into. He just came home with a left-handed Rem' 700 BDL wood-stocked .243 and wants some loads made up for him. Barnes' book about cartridges talks about eratic ballistics with the .243 and I'd expect that to mean not only velocities but bullet performance as well from what I've read elsewhere.
Good luck in any event,
SS'