http://slidefiresolutions.com/

I'm shocked. What a cool little toy. It could go the way of the Akins accelerator. That is, initial legal approval, then in a few months ATF may write the mfgr back and say "No go, recall all of the products that you sold or you and your customers are in violation of the NFA."

But hey. It's something. I'll be waiting a while before I buy one just to see...I would hate to have to forfeit to the ATF something I payed ~$300 for.