Assault rifles in a 5.56 mm evolution: the fielding of new designs and the upgrade of existing...

The perceived shortcomings of the 5.56 x 45 mm Nato SS109/US M855 round in the US armed forces-led campaign in Afghanistan has provoked the fiercest debate about the optimum calibre for assault rifles since the US Army decided that the 5.56 mm M193 cartridge would supersede the Nato 7.62 mm cartridge as the standard calibre for its assault rifles 40 years ago. The pressing demands of the Global War on Terror, which is being fought largely in urban areas in Iraq, mean that new and upgraded 5.56 mm assault rifles will equip the American military forces and their Nato and non-Nato al