Interesting the .243 still is OK for big game in many states, but the .223/5.56 is not. Prvi's 75gr comes out of the 24" muzzle at close to 1800, and most of the other hunting rounds are 1300-1500.
The .243, 30x30, and 6.8 are really not that much better but are legal. New ammo and barrels have really closed the gap. States should really open up the 223/5.56 for big game.