N-570 isn't that easy to work with, but the performance should make the extra effort well worth it.
I recently got some, haven't had time to put it thru the paces. I'm trying it in the 26 Nosler instead of the standard 869. I'm also trying it in my 7RM with heavy bullets. It should work even better in your Mashburn.
I would love to see a QL print out on the Mashburn with heavy bullets. I'll bet n-570 will be at or near the top of the list.
DF
