In developing a system for entry into the U.S. Military's Next-Generation Squad Weapons trials, SIG Sauer has spent much R&D time, energy and money into optimizing the round required for these future firearms. One specification required for NGSW entrants was the use of a 6.8 mm round, and SIG's answer was a specially designed hybrid case for the bullet. Commercially, this unique cartridge design came to be known as the 277 SIG Fury.
To meet the velocity and energy needs of the U.S. Military while retaining a 6.8 mm round, it was necessary to increase the pressures used in propelling the round from the barrel. While the 5.56 NATO runs at pressures of around 55,000 PSI, the new 277 SIG Fury required chamber pressures around 80,000 PSI.
For guns and cartridges to withstand these increased pressures without failing, a revolutionary case design was created. The 277 SIG Fury has three components in the cartridge case, all of which work together to create more capable ammunition than has ever been seen before.
Watch American Rifleman's First Look video on the unique design of the 277 SIG Fury above.