Buddy of mine did a 9tw, 90tgk with a stout load of rl26 behind it, 3830fps shoot sub half minute. Another friend of mine just built a 30" 10tw, his fireforming load of 56gr rl26 with 87vamx is going 3800. I predict he'll be over 4k with full pressure loads. I built a 24" 6saum. Only have 140 rounds down the pipe, but 115dtacs shoot tight at 3230fps with Rl23. I'll be jumping up to RL26 and N570 as I want to be over 3300fps and not into pressure.