Were they able to get their hands on the military hybrid steel base Fury brass somehow? Because the consumer market 277 fury brass seems to just be standard pressure large primer brass. (it's almost like SIG is begging for another lawsuit with that one...)
Better off to use small primer brass if trying to push it, lots of us shooting that at well above the 80k/psi and getting good life out of it.
But then again I was using regular large primer 260 lapua brass with 139's scenars and was shooting them around 2900fps with N160 and had some room left to go. When I put that barrel on a new action/stock I'll neck down some palma brass and try it out with CCI450's.