Unless you are a class 2 manufacturer, it can't be done legally.
Now, there may be registered DIAS or Lightning link available that will work, but those items are the "machinegun."
No post 1986 conversions for civillians.
"Those who live by the sword are probably pretty f***ing good at it."
"Instructions for a successful gunfight: Front Sight, Press Trigger, repeat
as necessary." - B. Braxton