Beginning his career in pornographic films in 2004, Gunn was soon recognised as the 2005 AVN Best Male Newcomer award. He likewise received the 2006 AVN Best Supporting Actor for his role in Pirates and a second AVN Male Performer of the Year for 2007.

He was married to porn actress Rita Faltoyano from 2005-2008. When asked during an August 2007 interview if there was a romance between him and fellow porn star Ashlynn Brooke, Gunn's reply was, “I think we are becoming something more”. Gunn and Brooke have since ended their relationship.

In 2009, Gunn directed and starred in a 3-D choose-your-own-adventure movie titled Cummin' At You 3D.

In 2010, he appeared in Entourage (TV series), Season 7, Episode 10: Lose Yourself.