I have a nice opportunity to purchase a Tikka rifle in .243 caliber for $400 - my question is what should I expect in the accuracy, recoil, and energy left at 300-400 yards department from the .243?  I've never owned one before or shot one before.

My experience has been with .308, .223, and 6.5x55 - and I was planning on getting a rifle either in .223 or 6.5x55 for target shooting, varmint/deer hunting, and as a rifle my wife could use.  I've read up a little on the .243 and it appears to be quite popular and useful for varmints and deer, more so than the .223 caliber.

Just wondering about accuracy potential, range, and energy left as compared to a 6.5x55 and .223 - already have a .308 and it is a little too much for the wife.

Thanks for the opinions and help, guys :)

Sorry I can't help you with the caliber of your choice, as I don't own a .243, but I do own 2 Tikka Whitetail Hunters, one in .308 and the other in 300WinMag and I absolutely love them. I hope you took a look at the .270 before you decided on a .243. As I said, I don't have a .243, but it wouldn't be my choice for a rifle intended for deer.
If you're concerned about recoil for the wife, I can attest that my Tikka 300WinMag is a pussycat. The first time I had it out, I used Federal 180gr. Sierra pro-hunter soft points and was surprised at the lack of recoil.
Sometimes guns in the same caliber, but different manufacturers will have much different felt recoil characteristics.
Good luck with your purchase.

You need not worry about the accuracy potential of the 243 cartridge. It is based on the 308 casing as is the 7mm/08, which like it's parent the 308 is known for its accuracy. The 243 makes a superb long range varmint cartridge and is completely adequate for deer hunting. I have deer hunted a bunch with the 243 and have not noticed any difference in taking them down between the 243, 7X57, 270 or 30-06. I will say that I would rather have the larger calibers while I am stalking or still hunting just for the extra punch if a nasty hard angle quartering shot was my only choice. If I am stand hunting there is no deer on this continent that is going to take a 100 gr. 243 in the boiler room and live long enough to lead you on a chase over the hills. In fact I have never actually had to track a whitetail down that I shot with our 243's, all have died with in sight of taking the hit.
Good luck,
Tuco