When Scoot McNairy’s voice first came over the phone, I was startled to hear a Texan accent. I should not have been — I had read that he grew up outside of Dallas — but I had just watched him act in two films, “Killing Them Softly” and “Argo,” in which he disappears so fully into two very different characters, I had all but forgotten he came from anywhere. You don’t expect a chameleon to speak with a twang. In “Killing Them Softly,” directed by Andrew Dominik and starring Brad Pitt, McNairy plays one of three guys who rob a mob-protected card game. In “Argo,” directed by and starring Ben Affleck, and based on real events, he plays one of six American diplomats who were extracted out of revolutionary Iran in an outlandish C.I.A. scheme that had them pretending to be a Canadian film crew. McNairy, 34, shifts shapes again in “Promised Land,” a Gus Van Sant movie that opened Dec. 28, and, if these films are any indication, he’ll do so again in “Twelve Years a Slave,” directed by Steve McQueen and due out this year. But don’t call him an overnight success. Between long days of shooting yet another major feature, “Non-Stop,” starring Julianne Moore and Liam Neeson, McNairy spoke to T about muddying accents, the art of riding mechanical bulls and what he terms his “slow, slow break.”  You’ve got three major films in theaters in one month. Is it safe to say this is a first for you?  Absolutely. Yes, indeed. It is definitely a first. I’ve been doing independent films for 10 years, but one out of five didn’t see the light of day. To have three movies coming out at the same time — I probably will never have that again in my life.  One of your first big jobs was a Levi’s commercial in which you were thrown from a mechanical bull. As a native Texan, can you in fact ride a mechanical bull better than that? Were you holding out on us?  Yes. But that was the thing — I also knew how to pitch myself a good ways off of that thing. So when I went into the casting, I said, “You know, if you stick your foot in the stirrup, you can really throw yourself off of there.” Growing up, my friends and I would ride barrels that you tied to four trees with springs on them. A guy would get on each rope and rock the barrel back and forth, and it would simulate riding the bull.  You recently moved back to Texas from Los Angeles. Was Hollywood not for you?  I love L.A. It was an awesome place to spend my 20s, full of creative people, but I never wanted to stay there. It wasn’t necessarily Texas that I wanted to move to; I just knew I wanted to live in the country somewhere. My wife and I found this place in Texas that we really liked, so we packed up our stuff and moved. We live off of a dirt road. Our closest neighbors are a half a mile away. You can be as loud as you want.  Are you glad in a way to have hit your stride now, having had a decade of experience, rather than in your early 20s?  I can’t say that enough. I’ve been asked, “What was your big break?” I don’t feel like I’ve had a big break. It’s been a slow, slow break. I want my career to grow gradually. There’s still so much for me to learn. I’m just trying to take these opportunities to get better at what I’m doing.  In “Killing Them Softly,” you co-star alongside quite a lineup — Brad Pitt, James Gandolfini, Richard Jenkins, Ray Liotta. What was it like to walk onto that set?  I was excited about getting the job, but I didn’t really have time to think about it too much. I was just focused so much on the work and doing a good job. I really love Andrew Dominik’s movies. When you work with someone whose movies you really love and who you have a lot of admiration for, you turn into putty in their hands.  The film, about a kind of money crisis in the crime world, is presented as a parable of the financial crisis. You play a low-level stickup guy, Frankie. Did you have a real-life corollary in mind? Or was that theme more of an undertone for you?  For me, it was a hundred percent undertone. Frankie’s world was separate from all that. He was just trying to survive. He had gone into prison at the height of the economy and the boom and come out at the bottom, but the character himself wasn’t so conscious of it.  Your accent in that film seems very distinct. Where exactly are you supposed to be from?  The film is based on a novel ["Cogan's Trade" by George V. Higgins]. In the book, my character is from Boston. And the dialogue, the way that Andrew [Dominik] wrote it, he wrote certain words to sound very Boston. But the film is set in New Orleans. My take it on it was, yes, this kid is from Boston, but it’s a contemporary piece, and I found it interesting to muddy it — to make the accent more distinct as a sound rather than a particular Boston dialect. If anything, he’s a sick, malnutritioned kid from South Boston who’s lived all over.  Frankie could not be more different than the tense diplomat you play in “Argo.” At one point there is a scene where you speak almost entirely in Farsi. Did you take Farsi lessons for that?  I have two lines in Farsi in the beginning of the movie, and initially that was it. But throughout the shooting of the movie I was trying to learn different things to improvise in Farsi. There was a P.A. on set who spoke Farsi, and I was hanging out with him a lot. Then Ben [Affleck] told me, “All that stuff at the airport, I think we should do it in Farsi.” That was thrown at me three or four days before we shot it. I posted the words on a wall, and I would just stare at them and say them over and over again. I was like, “Oh my God, dude. This is the end of my career.”  Were you familiar with this little-known chapter of the hostage crisis before reading the script?  I was familiar with the hostage crisis but not this specific story. It was classified. They didn’t declassify it until, I believe, 1997 or so. As far as the story is concerned, it’s all pretty accurate.  There is a cooped-up, cramped feeling to the scenes, many of which take place in one house where your character and the other five diplomats are hiding out. Did the cast do anything special to prepare for this?  We all spent a week in the house we shot the movie in. No cellphones, no computers, just board games and magazines, all from 1979. We would sit around and have dinner and hang out. It was incredibly beneficial, I think, for all the actors to create our own organic chemistry.  You’ve got a pretty serious mustache in “Argo.” Did you grow it yourself?  That’s my mustache. It grows like a weed if you don’t take care of it.  You are writing a screenplay at the moment. What can you tell us about it?  It’s a film about redemption. And it’s kind of a “Drugstore Cowboy” story, but set in the South.
The actor, who appears in "Killing Them Softly" and "Argo," talks to T about his "slow, slow break"