Sorry I'm late to this string... I've been working a load for my Sendero over the last few months. Started with H1000 and didn't ever satisfactory results. Switched to Retumbo and worked my way up from 69gr in 1/2gr increments. At 72gr the magic happened, 0.33" 4 shot group at 100 yards, 0.010" of the lands, no pressure signs, 26 inch barrel. If you look around on the web, several others have had the same result. gun)
I recommend 7828 SSC or 7977. It's much easier to find, and works great with the 168 VLD's in the 7mmRM.