Sam Reid plays it posh again but has sights on less plummy parts

Sam Reid is having a moment. No. Scratch that. Sam Reid is having a year's worth of moments. So far in 2014, movie hounds have had reason to gasp over the 27-year-old's portrait of an 18th-century anti-slavery campaigner, in Amma Asante's Belle, and marvel at his depiction of one of the spoiled toffs who populated The Riot Club.

Reid fans should also stay tuned for Despite the Falling Snow, a cold-war espionage thriller, and Serena, a Depression-era drama costarring Jennifer Lawrence and Bradley Cooper.

“I haven’t been home for almost two and a half years,” says Reid. “I filmed them all back to back. So it’s really interesting watching them now, maybe two years on, and seeing how I’ve changed.”

Next week he'll appear as a well-meaning but hopelessly out-of-his-depth young British army officer in Yann Demange's '71. The nail-biting thriller, following a lone squaddie (played by Jack O'Connell) as he attempts to survive the civil and political strife of early-1970s Belfast, also makes room for such popular Irish talents as Michael Smiley, Richard Dormer, Martin McCann and Charlie Murphy.

The film's shoot, which jumped between west Belfast lookalike locations in Yorkshire, Blackburn and Liverpool, was completely nerve wrecking. "We spent a couple of weeks shooting the riot scene," he says. "And with every take the crowd seemed to get louder and more menacing. It was a very heightened set. I loved that. And I loved that it was an anti-military film. It's about the impossible situation that conflict creates around soldiers as individuals."

We're used to thinking about Sam Reid as a very English gentleman or a very upright officer. In fact the actor grew up on a cattle ranch in rural New South Wales. His mum's family is Irish. "She was a bit disappointed when she found out I'd be playing a British soldier in '71 instead of learning an Irish accent," he says, laughing.

So the faux Bullingdon Club depicted in The Riot Club must have seemed very foreign. "It was like being in a historical drama," says Reid. "I think Freddie" – Fox, one of his Riot Club costars – "has met people like that. But he comes from a theatrical background, so that's not quite the same. For me it was completely alien."

How has he ended up getting all the plummy English roles? “I know. It’s one of those weird things. I was at Lamda,” he says, referring to London Academy of Music and Dramatic Art. “I learned my received pronunciation. I did my Shakespeare. But I don’t know how I ended up being all these British gentlemen. I’m going to have to play an Australian soon, to balance things out. Preferably a transported convict or something like that.”

Reid was named star student of his graduating class. Indeed, he had yet to graduate when he landed his first big role, as – wait for it – an English nobleman. His turn as the earl of Essex in Roland Emmerich's Anonymous, a historical conspiracy thriller that postulated that Shakespeare's plays were written by Edward de Vere, 17th earl of Oxford, parachuted Reid into a starry cast that included Rhys Ifans, Vanessa Redgrave, Joely Richardson and Derek Jacobi.

“It was the first audition I ever did,” Reid says. “Baptism of fire. I think maybe the casting director was under pressure to cast the role, because I was coached. I hadn’t seen the script. I didn’t know anything about the film. But she made me do it again and again and again. It’s only since then I’ve realised that they don’t usually help you so much during auditions.”

The Hunger Games star Sam Claflin was in the year ahead of Reid at Lamda. Theirs is a tale of two Sams: both actors feature in The Riot Club, and Reid replaced Claflin in Belle, when the latter was called up for Hunger Games: Catching Fire.

Reid is still cheering his good fortune. “Such an extraordinary true story. I mean, this incredible woman actually living in the lord chief justice’s house. And then working with Amma, who did such an amazing job bringing Belle to the screen. And Gugu, who was born to play that role. And touring America and doing Q&As and seeing how audiences responded.” He laughs. “How often do you get to say lines like, ‘I love her with every breath I breathe’?”

Reid has always loved acting. He and his older brother Rupert – Lock's lieutenant in the Matrix sequels – used to stage plays and cabaret in the cattle barn at home. His hero is Orson Welles. "I will never stop marvelling over Citizen Kane. It's impossible to think that that film was made by a 26-year-old. It's impossible to think that he had that confidence and that talent so early." Reid's not doing too badly, either.

'71 opens on Friday

High society How posh are the Riot Club?

- Max Irons: The star of The Host is the son of Jeremy Irons and Sinéad Cusack and half-brother of the People Before Profit TD Richard Boyd Barrett. He attended Bryanston School, a member of the Eton group – but was expelled. Quite posh and pretty Irish, too.

- Douglas Booth: The star of Noah and the incoming Jupiter Ascending was privately educated and is the son of the former managing director of both CitiGroup and Deutsche Bank's shipping finance divisions. Unlikely to be mistaken for a guttersnipe.

- Freddie Fox: Frederick Samson Robert Morice "Freddie" Fox is the son of the actors Edward Fox and Joanna David. Like Irons, he attended Bryanston. Currently appearing in Pride. His half-sister is Viscountess Gormanston. Proper posh.

- Ben Schnetzer: Also in Pride. His parents are the actors Stephen Schnetzer and Nancy Snyder. But he's an American, so that's just not cricket.