Most competition shooters don't use the 243 because of the low barrel life. However, a number of tactical shooters are running them for their flat trajectory and lower recoil.
the 243 can be a wonderful LR cartridge with 105/108/115gr bullets at the top of the class. Of course, this will require 8 twist barrels. Easy enough to acquire these days.
It will offer a 100 to 150fps boost to the smaller 6XC's and 6 - 6.5X47Lapua.
Jerry
What do you call long distance? The .243 is ok for target shooting at long range, but not for hunting. Energy drops off quickly past 300 yards.
"...ballistics program..." Ballistics programs are not infallible. The fact remains that the .243 loses energy fast and drops like a brick past 300 yards. Nearly 6 feet low at 500 and well under 800 ft-lbs of energy, depending on the ammo.
It is true that Ballistic programs are not gospel, nothing beats real DOPE from the field. However, on paper the .243 is a flatter shooting cartridge than the .308, and I can't wait to get mine up & running and see what she can do!
Tim H