Apparently the Marines are looking for a lightweight open-bolt heavy assault rifle to replace some of their M249 Squad Automatic Weapons. It’s sort of tough to figure exactly what the purpose of this weapon will be. It’s going to use the same magazines as M16s and M4s and will not have a quick-change barrel.
Maybe I’m missing something. If you’re willing to trade volume of fire for weight, why not just get a heavy-barreled M16?