[makr17]

If I had to make a guess, the US military is dipping into ammunition reserves because they hope/expect to stop using 5.56mm and 7.62mm rounds with the rollout of the XM-7 and the XM-250 (which both fire 6.8mm)

https://en.wikipedia.org/wiki/Next_Generation_Squad_Weapon https://en.wikipedia.org/wiki/XM7_rifle https://en.wikipedia.org/wiki/XM250