Professional comics fascinate me. Why would anyone voluntarily stand before a firing squad? Yet the potential for laughter lures the most insecure, angry, objectionable, self-loathing and hilarious personalities to the microphone stand nightly.

Director Christian Charles made a documentary in 2002 about Jerry Seinfeld’s attempt to piece together a show’s worth of material after his famous sitcom came to a close. Titled “Comedian,” the movie offered candid interviews with Seinfeld, Chris Rock, Colin Quinn and Bill Cosby as it presented an insightful glance into the hearts, guts and minds of these seasoned funnymen.

“Vince Vaughn’s Wild West Comedy Show” makes for a nice companion piece. On the heels of his 2005 hit “Wedding Crashers,” Vaughn handpicked four Los Angeles comedians and loaded them on a bus for an ambitious traveling concert tour captured on camera by Ari Sandel. The group intended to hit 30 cities in 30 consecutive nights. As you’ll see, Hurricane Katrina disrupted those plans but also gave Vaughn and his crew a unique human angle to explore (not exploit … big difference).

Vaughn’s “Wild West Comedy Show,” however, is light on laughs, so the picture only half works. Clips from the comedians’ live sets are a definite weak spot for a documentary that’s supposed to be about comedy. The sharpest performer is Sebastian Maniscalco who, we learn late in the film, isn’t even a full-time comic. He pays his bills by waiting tables. Foul-mouthed and bitter John Caparulo reminds me of a young Larry the Cable Guy. I forget large chunks of his material but recall he wore the same white T-shirt and blue baseball cap for the entire 30-day shoot. Ahmed Ahmed, an Egyptian comedian, bases his entire act on his Middle Eastern appearance. In off-stage interviews, he says he is forced to address his heritage. I understand that. But there’s no reason that has to be his lone joke.

The professional comedians are upstaged at almost every turn by Vaughn’s guest stars. During a rehearsed sketch on stage in Hollywood, longtime collaborator Jon Favreau suggests that anyone could have played Vaughn’s role in the iconic buddy comedy “Swingers.” The challenge opens the door for -“Dodgeball” star Justin Long to do a pitch-perfect Vaughn impersonation. Vaughn himself is the ideal emcee for such an unpredictable stage show. His banter carries interactions with Dwight Yoakam or best friend and “Wild West” producer Peter Billingsley (the famous kid actor best known for “A Christmas Story”).

So while “West” isn’t consistently hilarious, it is insightful when trying to better understand the unique individuals drawn to this field.