About three weeks ago, the Ultimate Reloader YouTube channel had a video in which he pushed Alpha Munitions 308 brass to an estimated 103,000 psi in several increments, so you might be able to glean something from that.
The issue with an AR10 is the bolt strength. With the XM7, the bolt is made from a fancy alloy to deal with the added force.
There was an interview clip from Ron Spomer where a SIG employee mentioned that there have been some accuracy issues at full pressure and future civilian hybrid-cased ammo will be closer to 70,000 psi. I wonder if this is the dreaded "bullet nose slump" issue seen around 2010 from some Berger .338 bullets with spicy magnum rounds. IIRC, the acceleration was so great that the ogive of the bullet sometimes deformed in the barrel. Berger began running thicker jackets to deal with it. I wonder if bullets designed for the 270 might exhibit the same thing from the 277 Fury?
The issue with an AR10 is the bolt strength. With the XM7, the bolt is made from a fancy alloy to deal with the added force.
There was an interview clip from Ron Spomer where a SIG employee mentioned that there have been some accuracy issues at full pressure and future civilian hybrid-cased ammo will be closer to 70,000 psi. I wonder if this is the dreaded "bullet nose slump" issue seen around 2010 from some Berger .338 bullets with spicy magnum rounds. IIRC, the acceleration was so great that the ogive of the bullet sometimes deformed in the barrel. Berger began running thicker jackets to deal with it. I wonder if bullets designed for the 270 might exhibit the same thing from the 277 Fury?