I found IMR 4064 to be excellent for velocity and accuracy in my 338-06 and my 35 Whelen.
That's pretty close on the Burn Rate Chart to the old 338-06 classic, 4320, and another popular one, RL-15, So, no reason why it shouldn't work.
I got a can of Vv n-150, which is Nosler's accuracy powder for their 180 NAB. Got some of those, too, blems at SPS. Back when I had a 338-284, the 180 NAB over 53 gr. RL-15 was a good load. I plan to try n-150, H-380 and RL-15 with those bullets.
I'll also try H-380 with the 160 TTSX and 210 NPT, save the Varget for my 7-08 and 22-204..
DF
