A 243 surpassing a 30-06 at long range?

A 243 with proper bullet and loading versus a 30-06 with crappy low BC bullet yes. But head to head both with similarly matched loadings, not hardly.

Go back to federals website where you got your 243 data from. This is what the site has on it.

243 100gr SGK 2960fps@ muzzle 2040fps@500yds w/925ft.lbs. 39.9 inch drop

30-06 165 SGK 2800fps@muzzle 1910fps@500yds w/1340ft. lbs. 45.2 inch drop

This is still a bad comparison because these two bullets have basically the same BC(notice almost identical vel. drop) with the .308 having a slight advantage. The .308 should be much higher.

I am failing to see the grave advantage that you say the wonderful 243 has over the helpless 30-06. Both of the bullet drops would preferably have to be dialed in as 3 feet of holdover with a low power hunting scope would be tricky. That leaves the 400ft.lb. difference in energy that the 30-06 has over the .243.

Im not doubting the killing power of a properly loaded 6mm bullet in the hands of a skilled rifleman with accurate ranging techniques, but I wouldnt suggest 500 yard shots on deer with the low BC bullets that are factory loaded along with a low power non-target turretted scope.