According to the YouTube description, this non-standard M1911A1 or A3 is a home made full auto.
It was manufactured just before the cut off date in May of 1986 and has since been registered as a sub-machine gun.
There are only 4 or 5 of these in the United States. Notice the unique fire selector on the right side of the slide.
These were manufactured by an armorer working with the US Army in Korea. It shoots around 1,000 rpm and is wildly uncontrollable.