That is completely dependent on the weapon and caliber being fired.
M-14 firing .7.62 NATO (.308 Winchester)? Uncontrollable.
MP-5 firing 9mm Parabellum? You can write your name.
Concur. Certain full automatics can be controlled with the proper training. And some people are better than others.
I had a Corporal in my platoon that was muscular, about 170 lbs and about 5'9". He was the only person I have ever seen that could accurately fire a M60 MG from the shoulder. I watched him cut down a 4" diameter tree shooting at full automatic and at about 150-200 yds. He did it in three 5-8 round bursts. I would have had a hard time doing the same thing with a M60 placed on a tripod and locked in a T&E (Traverse and Elevation mechanism).
Dishka firing .50 cal? Only the first round is anywhere near the target.
I’ve never fired an M16, but I have fired an AR15 as rapidly as I could pull the trigger, and the recoil was surprisingly mild.
Strangely enough it works that way in laser tag too - if you fire all the time you make yourself a target.