Gunpowder residue explosion at indoor shooting range - GIF and video

[ranald]

OK 4 real. not AK 4 seven. Not Funny!

[Frank S]

kid didn't hardly know what to do once the weapon went full auto. Almost turned the situation into a deadly disaster.
If there hadn't been a range instructor grab the fore grip there is no telling how the outcome may have turned out.
But my question is did the weapon have a worn sear or a faulty sear spring that caused it to go full auto or did the selector get moved somehow to full auto then once it started continuous fire did the kid panic and put a squeeze hold on the trigger.
In basic We started training for full auto with the M16 A1 by starting out with only 3 and then 5 round magazines working up to a full 20 round magazines then to rapid swap out firing 5 full magazines in a timed exercise. My favorite range fire though was with the M60 although I hated cleaning it