Semi-Automatics are usually measured in Semi-Auto Rates of fire which is the maximum number of times that the weapon can be ACCURATELY fired within a minute. 45-60 rpm is pretty standard for this type of measurment.
What you are probably looking for is the cyclic rate, which is where it measures how many rounds you can put down range with no aiming or magazine changes.
Cyclic rate of a M-16 is 700-950 rpm. I am sure this is out of the semi-auto mode.
You probably won't find an actual cyclic rate for Semi-auto mode as it is as many times as your little finger can pull the trigger in a minute and would vary so much with different users.