Back when I was running a .240, the best results in my rifle (a Weatherby ULW) MRP and Magnum turned out to be the two top powders with 90-100 grain bullets.
MRP happens to be what Norma loads in the Weatherby factory ammo. I found this out breaking down a round and comparing the charge and granules to my collection of Norma powders, but Reloder 22 should work about as well, since if MRP and R22 aren't exactly the same powder they're very close.
Then I tried Magnum and it worked at least as well, and Nosler now lists it as the powder they got the best accuracy from with 95-100 grain bullets. The load I eventually settled on was enough Magnum to give 90-grain Nosler E-Tips just under 3400.
