Jenrick and others point out that full-auto on sub-guns made sense because pistol rounds are not reliable man-stoppers, and because a good sub-gun allows for adequate control of automatic bursts. Of course, any time you can carry a sub-gun you can carry a small carbine that shoots a reliable rifle round, so tactical units have gone to carbines and apparently the argument for full-auto on tactical weapons with stocks seems to have gone away.
But to bring this back to the original question: Isn't this an argument for full-auto handguns? Tactical professionals for a long time thought pistol rounds were sufficiently underpowered that when shooting was warranted it was advantageous to get a handful on target with a single trigger pull. Apparently the extra time it would take to pull the trigger for each shot was a tactical liability. Now that we have good carbines and "PDWs" the only time you're going to be stuck shooting a pistol round is when you have to use a pistol to defend yourself.
So I'm an armed citizen carrying a concealed Glock with 17+1 and I have to use lethal force to stop an attacker. I'm not expecting to get into a protracted gun fight, but now that the scenario has escalated to shooting the difference between me winning and losing could very well be measured in fractions of a second. And that's the difference between full-auto and semi-auto in getting multiple rounds on target. (And note that with my Glock I get *six* 3-round bursts before I have to reload!)
I.e., following this logic it sounds like for personal defense weapons full-auto makes the *most* sense for (high-capacity) handguns! Except that concealable handguns (presumably lacking a stock) are the most difficult to shoot on full auto. I haven't had the privilege of shooting one yet, so can a reasonably trained shooter use them effectively on full auto? Or is it always going to be better to reset the trigger after each round cycles the action, even though that takes more time?
As for the question "How many civilians have learned that important lesson about fire control?" It's part of all good training. If full-auto were a handgun feature I would teach burst control right alongside muzzle control, trigger control, clearing stoppages, tactical reloads, etc. It would be part of the whole "don't do it like in the movies" spiel. "Don't hold your gun sideways like a gangster. Hold it with two hands when possible. Don't put your finger inside the trigger guard until you're on target and ready to shoot. Don't spray and pray." And controlled bursts would be part of tactical drills just like drawing from a holster, etc.
The other scenario raised for full-auto fire was "stopping" a vehicle. Of course nobody looks for a scenario where they have to disable a vehicle with anything less than a 40mm grenade or .50 BMG. But my original question was whether there are any non-military tactical scenarios in which full-auto is an advantage, and so far it sounds like this might qualify. Of course you can't "stop" a vehicle with small arms, but you can't "stop" a person with gunfire either. You shoot a person to get them to stop by preventing them from continuing to pose an imminent threat to people or property. If a vehicle poses an imminent threat to people or property of course your best bet is to stop the driver. But there may be multiple assailants capable of operating the vehicle, or maybe the driver ducks down below the dashboard so you can't reach him with your rifle. Now the question is: Do you enjoy a tactical advantage disabling the vehicle with a full-auto rifle over a semi-auto version?
(I'm not even sure what the tactics are for disabling a vehicle with a high-capacity rifle. From the side I would probably try to lay fire into the place the driver should be even if I can't see him. But from the front and rear I don't know whether it's better to put a few into each tire or if you can hope to hit the gas tank in the rear or the battery, belts, eletronic controls, or fuel lines in the front by firing randomly into the engine compartment. In any case, presumably being able to dump 30 rounds in 3 seconds instead of 5-6 is a tactical advantage in this niche scenario?)