I won't use anything other than IMR-4064 for .243. I've had stellar success with it in years past.
Not reloaded for this cartridge for a long time, but I recently got my Father's .243 and am contemplating running it through its paces just to see what I can wring from it.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.