I've tried Rel-17, rel-19, Rel-22, IMR4320, IMR4350, IMR4064, H380, H4831, Win 760, and just about any other possible powder and had to chose between accuracy or speed. After doing some research, I think I'm going to try N150 next. I read an extensive test and that powder seems to give the smallest groups and greatest velocities with the 120-150gr bullets in the 284.
If you can find some of it, it might be worth a try.
I read the same report which is why I went with RL15. It was the second most accurate powder tested and is also top in the Nolser manual.
