I shot the 155s in my 7 STW with RL25, RL26 and H1000 this morning. By way of intro, my STW has underperformed by about 200 fps below published max data in every powder I've tried. Just as I was about to pull the barrel, along comes Hammer to the rescue. While I did not find what I was hoping for with RL25 or RL26, I did pick up 160 fps with H1000 over the Berger 140 grain VLDH with no signs of pressure. Accuracy was exceptional with the largest group just under .7" at 100 yards.
Results:
RL 25 RL26 H1000
79.0 - 2,903 76.5 - 2,985 80.5 - 3,147
79.5 - 2,985 77.0 - 3,001 81.0 - 3,197
80.0 - 3,001 77.5 - 3,071 81.5 - 3,248
80.5 - 3,071 78.0 - 3,049 82.0 - 3,299
While I will continue with H1000 until I find max for my rifle, rereading Steve's initial post discussing the need for faster than normal powders data got me thinking about other powders. I ran Run RL19, H4350 and N550 in QL and max safe load came up to 3,077. Assuming I get an additional 300 fps, it only gets me back to where I think I can get with H1000 and I have lots of H1000. Case fill % may also be an issue with some faster powders. Think I'm going to hand tight until more data becomes available.
I did pull the string on the 124 6.5s. Bad timing as I just loaded 200 rounds of 6.5 CM with 130 Berger AR Hybrids, but I'm highly attracted to new shiny things. Time to free up some brass. I'm very satisfied with getting 2,977 with 43.5 grains of RL16, but who can say no to more speed or shiny things.