Re: .243 ammo for deer?
I've taken deer at 3 deer and 2 antelope 400+ yds with 75gr Vmax bullets all with one shot kills, 3 dropped in their tracks and the rest ran less than 50 yds... and I've taken them at 75 yds with 100 gr El Cheapo factory stuff, some drop where they stand, some run 100 yds or more. Deer where we live are BIG bodied and can be a bitch to bring down no matter what you shoot them with.
The 243 WILL kill any deer in North America as long as you know where your bullet is going to land. The adrenalin the deer has pumping through his pipes will determine if he runs and if so, how far. Even the big guns and the big heavy hitting bullets are no guarantee that it will fall dead in his tracks.
TSX, VLD, AMAX, Soft Point, Hollow Point, Boat Tail, Flat tail, Round Nose, yada yada yada. Know the ballistics of you're load, find what the energy delivery is at a given distance and stick within the range that you can make a successful shot in the kill zone.
That's about all it boils down too.