New rifle, bigger bullets: Inside the Army's plan to ditch the M4 and 5.56
By: Todd South, May 7, 2017
After carrying the M16 or one of its cousins across the globe for more than half a century, soldiers could get a peek at a new prototype assault rifle that fires a larger round by 2020.
Army researchers are testing half a dozen ammunition variants in “intermediate calibers,” which falls between the current 7.62 mm and 5.56 mm rounds, to create a new light machine gun and inform the next-generation individual assault rifle/round combo.
https://www.armytimes.com/articles/new-rifle-bigger-bullets-inside-the-armys-plan-to-ditch-the-m4-and-556
