let's say the US Army does have some secret sauce penetrator round cooked up for the M7, some kind of saboted DU shit like oxide shot in that one .308 video. Let's say it goes through modern body armor like butter.
If you're a chink and all of a sudden people are getting shot in the plate and dying, how big of a morale hit is that?
Is it true overmatch that's worth ditching the advantages of the M4?
Just a little thought experiment.
DUDS video for those who haven't seen it https://www.youtube.com/watch?v=DtdmsZ4Csn8&t=219s