Posting this for a friend but a lot of great minds here. Remington 700 .270 Win stock rifle. Remington stock 270 win ammo (not reloads). Had been functioning fine and shot several rounds from the same box of ammo prior to this one (with stock accuracy as expected). This round detonated (misfire) and sprayed shooter with brass, powder and blowback (no major injuries thankfully). The bullet cleared the barrel (barrel clear) but locked the action up tight. Bolt removed (with great difficulty and breaking lever off) and this is what the case looked like after. Bolt neck fractured. The case primer pocket is 5x expanded. Dents in the case neck occurred while removing case from action. Any thoughts?