Not sure about in the states what kind of size your deer reach but down here in Oz I would not recommend a 243 for effectively taking more than a fallow deer. I have personally used both 87 and 95 grain bullets on these, goats, kangaroos and wild sheep and pigs. In saying this however I have seen other people using a similar setup fail to effectively drop large pigs with them, I.E. exploded on the shoulder plate or glanced off of heavy bone and caused little more than a painful wound on the animal.
Personally for most of the species down here, I would prefer a 25 cal or larger (270 7mm or 308 would be the choices for sambar and large reds) and it is in fact stated that 270 is the minimum caliber to be used for hunting sambar.
The 243 performs best on game weighing between 40 and 60 kg's with a probable maximum of around 80 to 100 kgs (180 to 200 lbs.) This is the ethical range, and yes people have taken much larger game (myself included) than this with them but beyond this range the chance of not cleanly killing/wounding the animal increase dramatically. On game at the upper end of this range for the general shooter I would recommend a range of less than 250 yards.
Personally I consider the 243 a bit underpowered as a deer rifle, but, if I stumbled across a deer within effective range and I had heavy enough loads with me I would probably use it if I had nothing bigger. Generally in the past if I had the 243 with me I also had the 30-06 as well.
anyway thats my 2 cents worth on the topic, I am sure that there will be guys out there who will tell you they have taken elephants with 22 shorts and that barnes x bullets perform miracles and stuff, but I would buy something a little bigger for peace of mind when it comes that time where the 243 lets that prize rack get away.
Trav