[4] The 6.5mm Grendel cartridge was first unveiled in May 2003 at the Blackwater Training Facility in North Carolina, where it remained supersonic at 1,200 yd (1,100 m) range and out-shot the 7.62mm NATO with only half the recoil.

[5] Since its introduction, it has proven to be a versatile cartridge and is now expanding into other firearm design platforms including bolt-action rifles and the Kalashnikov system.

Constrained by the dimension of the STANAG magazines, the Grendel's designers decided to use a shorter, larger-diameter case for higher powder volume while allowing space for the long, streamlined, high ballistic coefficient 6.5mm (.264 cal.)

It retains greater terminal energy at extended ranges than either of these cartridges due to its higher ballistic coefficient (BC).

[citation needed] Three types of 6.5mm Grendel ammunition produced by Prvi Partizan of Užice, Serbia, will be tested for use with these rifles.