Actor Johnny Depp has fond memories of his first machine gun.

He was a kid growing up in Owensboro, Ky., and around age 5 or 6, began shooting .22s, then moved to .38s, .44s and .45s. Then he got his hands on a relative's Thompson submachine gun.

"I butted it up against the tree 'cause it tends to ride up on you," says Depp, 46, who relives the moment, complete with shooting sounds. "My pop came in and grabbed it, so it didn't go anywhere."

Guns are a topic of conversation for Depp, given that the superstar is talking about his new film, "Public Enemies," the Michael Mann gangster epic in which he plays infamous 1930s bank robber John H. Dillinger.

But firearms crop up in other ways too, like the first time Depp met his longtime friend, the late Hunter Thompson. Depp — who played the author in the 1998 film version of "Fear and Loathing in Las Vegas" and recently finished work on an adaptation of "The Rum Diary" — went to Thompson's house in Colorado, where he complimented the writer on a 12-gauge shotgun hanging on the wall.

"He said, 'Oh, yeah, wanna fire it?' " recalls Depp.

Thompson told him to hold a couple of small propane tanks.

"I got a cigarette hanging in my mouth and he starts handing me these little matchbox-shaped square bits and told me to tape them to the sides of the tanks. I said, 'What is this we are taping to the side of this propane tank?' And he said, 'Nitroglycerin.' "

Depp opens his black eyes wide: "I chucked my cigarette in the sink!"

Later, he shot the tanks in Thompson's backyard and "there was an 80-foot fireball. I think that was my test," he says.

It's hard to imagine that Depp wouldn't ace any exam that tests the limits of a free spirit. He's perhaps the most eccentric of all the major male movie stars. Ironically enough, he's practically the only actor who didn't ascend to superstardom with shoot-'em-up roles.

Depp's done more than almost any other actor in Hollywood to expand the on-screen concept of masculinity, bringing "guyliner" to mainstream America well before Adam Lambert ever appeared on "American Idol" as well as a vision of male heterosexuality that maintains an element of the feminine and tons of rebelliousness.

After finishing "Rum Diary" in Puerto Rico, he flew to Los Angeles to pick up his "kiddies" (a 10-year-old daughter and 7-year-old son with longtime love Vanessa Paradis), accompanied them to France where they live, then flew to Chicago for a "Public Enemies" premiere, then back to California for a second screening at Los Angeles Film Festival.

Depp has appeared in almost 50 movies, but for much of his career — the "What's Eating Gilbert Grape" portion — he seemed a bohemian artist, wary of the stardom that could be his given his on-screen charisma. More recently, he seems to have made peace by embracing the medium's mythic and myth-making potential.

Depp hasn't played many ordinary citizens. He seems to prefer portraying an eye-lined pirate ("The Pirates of the Caribbean" trilogy), the creepy candy impresario ("Charlie and the Chocolate Factory"), the dreamy creator of Peter Pan ("Finding Neverland"), and the Mad Hatter from the upcoming Tim Burton version of "Alice in Wonderland."

The vivid looks of his characters sprout from Depp's own imagination.

"You get these strong images in your head and you can't shake them," he explains.

When preparing for a role, he sketches the character, or paints him in watercolor, allowing his brain to bounce along its own idiosyncratic path. Capt. Jack Sparrow's coal-rimmed eyes weren't inspired by glam-rock but by Berber nomads who lined their orbs to protect them from the sun.

"I always do (sketches)," says Depp. "Don't know why. Just to kind of get an eyeball on the guy first."

Disney recently released early images from "Alice in Wonderland," and Depp's Hatter, of course, looks more than a little mad (some believe that hatters frequently suffered from mercury poisoning, as mercury was once used to cure felt).

"The orange-hair thing was very important. I think he was poisoned, very, very poisoned, and it was coming out through his hair, through his fingernails and eyes," says Depp.

Dillinger fits perfectly into Depp's personal canon of larger-than-life rebels and outsiders. The outlaw also holds sentimental appeal for the star, whose Kentucky hometown is about three hours from the gangster's birthplace in Mooresville, Ind.

Dillinger was just a punk when he was sentenced to nine years in the penitentiary for his part in a drunken mugging. He emerged as a hardened criminal, led a gang on a dozen bank robberies (hauling away $300,000 — about $4.8 million today), escaped from prison a couple of times, had a shootout with the FBI, and finally went down in a hail of bullets outside a Chicago movie theater.

While researching his role, Depp searched for a voice recording of the outlaw but couldn't find one, although a recording of Dillinger's father turned out to be revelatory.

"Hearing Dillinger's pop ... these are guys I know. I knew him then," says Depp. "I wanted to salute my grandfather through Dillinger and salute Dillinger through my grandfather. You know, my grandfather drove a bus by day back in the '30s and ran moonshine by night."

Depp says he felt a connection to Dillinger in old films Depp watched for hours on his family's black-and-white TV.

That was in Florida, where his parents ultimately moved and split up. Young Depp was enthralled with Dillinger as well as Charlie Chaplin and Buster Keaton.

"I guess the era got me, the '30s, '40s and even the '20s. I was fascinated with the old Bogey movies, with Cagney movies, or even Fred Astaire."

Undeniably, Dillinger the myth remains bigger than Dillinger the man, even though "Public Enemies" is based on Bryan Burrough's nonfiction book about the gangster.

"The title of the film is 'Public Enemies,' but I don't see John Dillinger as an enemy of the public," says Depp.

He points out that Dillinger's prime antagonist, J. Edgar Hoover, wreaked more havoc and misery during his 40-year tenure atop the FBI than Dillinger did during his 18-month crime spree.

"I mean, who's the real criminal?" Depp asks.

The movie is "bloody and brutal," but it takes place during the height of the Depression, during a wave of foreclosures and bank failures. "People at certain points just had to take up arms, did they not?"

Still, even in these troubled economic times, it's hard to imagine the public romanticizing a similar outlaw figure.

For Depp, the real difference is the corrosive media attention.

"Today, if there was a Robin Hood-type guy out there — we are in an age where we sell our privacy to television. Everyone out there has a camera, and a cell phone, and a BlackBerry, and in less then 10 seconds it's on the Internet. So he would have been sold out just like that today," says Depp, snapping his fingers.