'Wanted a lightweight, long-range mountain shooter, so in 2006 (inspired by the knowledge of the 264 WM, shooting many 300 WMs and 257 Wbys (and a knowledge of handloading/ballistics) I necked down a 300 WSM to 264 WSM (best thing I ever did, ballistics-wise) and asked Mark Bansner to make me a gun to my specs. 3200-3400 fps 130-140 gr, 3150 160 gr-has taken game all over the world (and some impressive shots 450-750 yds at times in bad weather and good.) The original win mag was my goal, but riflewise and ballistically, the shorter case/action/bbl won out. 'Shot the bbl out of it (Lilja) after 3,000ish rounds and just had Bansner re-barrel it w/ 2" longer (25"), faster twist/less grooves and now it seems to have adopted the even more superior bc/sd 150-160 gr pills at increased V. 'Wasn't sure Mark would have my pet redone by deer season this year, so put together an equally nice 6.5-300 Wby (slightly larger package but very, very nice long range, all-weather shooter!) both shoot nearly one hole groups. And I am reminded above the original carbon steel barrels would get burned out prematurely by the original 264 especially when hot hand loaded. High quality stainless is the way to go in these high velocity guns. Also the selection of 270 bullets was unimpressive for a very long time. The only reason for the higher velocity rounds is to extend the effective range. If suitable high BC/SD bullets are not available there's just no point. 140 grain is the beginning of good in 6.5.