Has anyone had luck with the trigger addons that allow burst and auto.  

Danger, Will Robinson!  Danger!!

For the love of God NO!

Back when I was young(er) and stupid(er) I bought one of those "Hellfire" conversions at a funshow. It was probably the most frustrating and worthless piece of shite I was ever braindead enough to buy. It went into the dumpster at the range roughly 48 hours after it was purchased.

It's supremely embarrassing to admit publically that I actually paid money for one of those things. Consider it a public service for the common good. In short, save your money.

Here is a visual for the cognitively impaired (like me say, 10 years ago):

I expected this or or maybe even

What I actually got, was and