This shot is probably based on Paul le Paul’s “Rapid one hand deal” but this one is performed by the index finger and not with the thumb.
This is the technique: Index finger on right corner of the deck and the rest of the deck is holding it on the most right ends with the thumb and the middle finger. The index finger curls the top card back towards the thumb and releases it when it bends inward. The card shoots forward from the deck. (see picture)
This can also be done with a single card without a deck: hold the card between your index and thumb and flick your index finger inward to the thumb. You can choose to bend the card inwards or outwards. Some people prefer to do the single spin with the middle finger.
If you repeat the action fast it looks like a shooting machine.
Riffle the cards in a table riffle way but with an angle of about 100 degrees. Keep the top right card as the last card of the riffle. If you push the cards flush, with the right index finger you do like you do the martin lewis spin on the short side of the cards. The card will shoot forward as you push the cards flush.