The military 5.56mm ammo may indeed be loaded to higher pressures than commercial .223 Remington ammo. But ifit IS, this is news to me. I would certainly be interested if someone could provide an AUTHORITATIVE source for this assertion-like SAAMI specs, not just "Joe Blow told me...."

Regardless, no-one is going to load ammo, GI or otherwise,to pressures beyond the elastic limits of the brass cases. So I doubt that firing GI ammo in modern, strong bolt action .223 riflessuch as the Remington 700 will result in blown cartridge heads..... IF this has happened, I'd like to see the evidence! (It is true that 5.56mm GI brass has less capacity than commercial stuff, so if one were to load GI brass with a max load developed in commercial cases, it could indeed cause difficulties!