Sig Sauer's 6.8x51mm Hybrid Ball Ammunition was initially developed for the U. S. Military's Next Generation Weapon Systems, offering greater stopping power and accuracy over traditional 5.56 and 7.62 NATO rounds. It features hybrid case technology where the base of the cartridge is made from stainless steel and is attached to the bass case via locking washer. Because steel has a far greater yield strength than brass, the muzzle velocity is increased and the trajectory is flattened. The energy on target is also enhanced, giving the projectile the performance of magnum ammunition with the size of a short action cartridge. The bullet is 113gr solid copper. Sig Sauer Hybrid Ball .277 SIG FURY/6.8x51mm 113gr Ammo 460rds/Can w/Solid Copper Bullets MH68MM113B-460