Jeff, re: H4350, when I was running 7/08s, I had some IMR4350 from using in 270s, etc. but it never metered worth a flip and I hated trickling, that said, I did try it briefly but never had the accuracy. I do think compressed loads was an issue, but it seems when Hodgdon came out with the SHORT CUT 4350, that SC seemed to find a home for many 7/08s. Users report good speed and accuracy, and it's a natural, top two for the 260 - the comp shooters use the H4350 SC and the H4831 SC as well.
My experience showed wonderful results with 4064, a tad faster on the burn chart, as 4320. The latter was my fav in 338/06, and LOOKS to be a great powder to try for 120-150 grain, likely 130-140 wt. 7mm-08 loads would do very well with 4320. I know 120s do well atop 4064, as Varget.
Never needed or got around to using, but RL15 and 120s are said to do very well, as RL19 with heavier bullets. Newer powders like RL17 warrant a hard look.
Hmmm, SuperPerformance Powder.....that's a catchy name, may have to look into that as well down the road.
