In need of some input fellas....

Good friend of mine has a Remmy Model 7 243 Win. with a 20" barrel. I'm looking to load up some 70g Noslers for him. In the past, I loaded 55g Blitzkings with Varget but that created a huge fireball and accuracy was only so-so.

Do any of you have a go to powder for a short barreled 243 Win. using 70g bullets? Most of the powders I have on hand are Hodgdon or IMR variety although I do keep R-15 on the shelf.

Thanks in advance!