Yes, yes, yes. The M4 the poor bloody infantry gets has the retarded 3-shot (or sometimes 2-shot or 1-shot, sorry bout that) burst mechanism that was thrown into the M16A2 as a way to eliminate the need to "waste" ammunition in training soldiers in fire control. In specific situations full auto is useful -- at close ranges, and in achieving instantaneous fire superiority as in a meeting engagement or counterambush. So SOF got the M4A1 which along with a couple of other tweaks has the auto-fire mechanism of original M16/M16A1 vintage.
Now that the Army has decided that other troops deserve rifle training too, this abortive burst gadget seems destined for the scrap heap. Ordnance and Quartermaster guys may try to resuscitate it, but in this iteration of the Army the combat soldiers are driving the train. (That will be good news for the Marines, who often get stuck with whatever the Army cooks up, for good or for ill. Marines are great troops, they deserve the best, too, not hand-me-downs).
Some HKs used to offer burst as a fourth choice on the dial (the others being safe, semi, and auto).
d.o.l.
Criminal Number 18F