.243 is better, but not necesarilly from a balistics standpoint. There is just a wider variety of bullets for .243and ammo is not only cheaper, but easier to find in stores that don't carry a full selection.

Really it is hard to say which is better for deer hunting when shot placement is the key to a successful harvest of a deer!!!

I just prefer the .243 because is a short action cartridge, cheaper to shoot and kills deer just as dead as the 25-06!

Either will do the job just fine. The advantage the 25 has is the ability to shoot 120 gr bullets. That being said my winter project this year is to rebarrel my Czech Mauser to 257 Roberts, haven't decided whether or to to go to the AI though.

Just remeber the 25-06 needs a 26"barrell to get those ballistics. If you have one in a 22" barrell knock off about 200fps.
Which one is better ? Not enough difference. Both work well.

my 25-06 is one of my favorite guns. I don't know if I can place it above my .270 though

I'm a .243 fan... I like the short action and the milder recoil.

As regards those discussing ballistics... The .25-06 is flatter. Comparing the most likely used bullets, 100 v. 120, the .25-06 is flatter by about an inch and a half out to 500 yards. I'd guess there aren't too many folks here who would notice the difference.

"Better" is absolutely subjective in questions such as these. I've owned both calibers, and could never tell that one deer was deader than another, though.

From Hornady:

Caliber- Bullet-Velocity/EneryMuzzle 100 yd. 200 yd300 yd 400 yd 500 yd muzzle, 100,200,300, 400, 500

243 Win 100 gr. BTSP LM InterLock 3100/2133 2861/1817 2634/1541 2419/1299 2213/1087 2018/904 -1.5 1.4 0 -6.4 -18.8 -38.2

25-06 Rem 117gr. BTSP LM InterLock3110/2512 2862/2128 2627/1793 2405/1502 2193/1249 1992/1030 -1.5 1.4 0 -6.4 -18.9 -38.6

Identicle bullets (other than weight) energy at 200 and 300 yards is highlighted for both rounds.It has long been believed that 1200ftlbs of enery is the minimum needed to kill a deer with a modern rifle. I'll take the 25.06's extra 200ftlbs at 300 yards, and be able to kill at 400 over the .243.
As for those people that say a .243 is a flatter shooter... well .4 inches flatter at 500 yards isn't enough to brag about, neither gun should be shooting at anything but targetsor prairie dogs at that range.

Not sure where this "long belief" comes from exactly. I've read 1200 ft lbs minimum for elk. I've read 800-900 ft lbs. for deer. I suspect that it could be done efficiently and humanely with a lot less than that if you're careful about where you put your bullet. I know deer get harvested here in Texasquite regularly using a .223, which only has about 900 ft lbs at 100 yards...