Quoted:
Thanks for the replies. A Liberal Gun Grabbing friend of mine today was talking about Donner's Manifesto. He pointed out just what you all have been saying. Even auto fire M16 are rarely used in that mode. Donner believed ARs should be banned. My friend picked up on this and its part of his Ban the AR argument. I wanted to hear first hand what combat vets had to say about this.
We have purpose built machine guns for automatic fire.
Don't get it wrong, automatic fire has a purpose, and our machine guns (M-249, M-240, M-2, Mk. 19, etc) get the majority of the kills for direct fire. Individual rifles get relatively few effects on targets when compared to our other weapon systems.
The US military has been built close to the German system, where individual riflemen are more for protecting the machine gun, and the machine gun is our most important organic weapon system in the infantry platoon. Everyone's position is built upon supporting that machine gun. You don't need automatic fire to do that.
We have been getting away from that mindset in some instances where it's not applicable, such as in MOUT situations, where a static machine gun position has less utility, but we're still supposed to prioritize placing machine guns over placing riflemen.