[Brad from Tennessee]

I guess it’s not around anymore but there used to be a device that could be attached around the trigger guard that would allow the shooter to fire bursts. I can’t remember the brand name.

[Deaf Smith]

It was called Tri Burst until it was outlawed. Seems other companies took up the name for products.

Later the was another assembly that allowed a second shot when the trigger was released.

[Drammach]

There is, or used to be, a trigger-device called "hellfire" that allowed for rapid fire bursts.

The "hellfire" device was being used at the waco TX. compound and was erroneously identified as automatic weapons fire.