New Army "Caliber Configuration Study"

[Tony Williams]

That, as well as other missions where an MMG is typically attached. In which case we're back to having two different calibers, and two different machine guns, which negates one of the fundamental premises of the GPC concept.

A GPC must be able to match the hit probability of 7.62mm at 1000m, which would be enough for the great majority of missions, even in Afghanistan. I've not heard of any small-arms attacks being launched against ISAF forces from longer ranges than that.

If a .338 MMG does make it into service, I would expect it to be commonly mounted on vehicles or sited in fixed locations for base defence (where the ammo weight doesn't matter). The reduced weight over the .50 cal would probably be of most value in carrying it to forward outposts and other positions, rather than on mobile patrols.