One Cartridge not a box: 277 Sig by Sig Sauer USA, using the Military Hybrid (Bi-Metal) case and loaded 150 Grain Accubond Bonded Polymer Tip projectile. Loaded to commercial firearm pressures. Muzzle Velocity is 3,120 Feet per Second, Energy 3,243 Foot Pounder per Square inch.

History of 277 Sig Fury of the cartridge:

The .277 FURY (6.8×51mm) cartridge was designed by SIG Sauer Company and announced by SIG Sauer in late 2019 for U.S. Military; however, it was not available to the general public until early 2022.The cartridge was designated as the “.227 Sig Fury” by the SAAMI as being a centerfire, rimless, bottlenecked, rifle cartridge and was designed for the United States Army’s Next Generation Squad Weapon Program (NGSW) project.

The cartridge has the same case diameter, length and diameter as the 7.62 NATO (308 Winchester) with the case throat necked down to accept .277 caliber (6.8mm) bullets, leading to an unbelievable 80,000 PSI (pounds per square inch) pressure.  

Currently chambered in the Sig Sauer MCX-SPEAR a gas piston AR-10 style rifle which has a $7,999.00 M.S.R.P. making it not for the average shooter