All you guys are off a bit...the "Generals" who took the original rifle for testing didn't like the cyclic rate which was a bit slower than what they wanted, plus they liked doing business with their old buddies who manufactured the powder they liked, so they changed the powder to up the rate of fire and used a specific powder that jammed the works.
The original AR-15 used by the early Special Forces working as advisors worked like a charm and was as effective as the AK-47 in adverse conditions.
The jamming was fixed by chrome plating and the handle was installed because some nit wit General wanted one. They didn't want to admit that they had screwed up a beautifully designed and effective weapon.
I, um, did a little work years ago on these toys.