Is this a trick question? If you are a 243guru, then you should already know the answer.
100gr Hornady Interlock over IMR-4350 for the win!
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THIS
But I'll admit I used 95 NBTs for quite some time with excellent results. Only reason I dont use them now is my current .243 doesnt like them.....which is odd cause Ive never seen any gun that didnt like NBTs.