With a name like Machine Gun Preacher, you half expect the hero to walk around with a flaming skull. No, it's not a Marvel Comics film: it's based on real-life Sam Childers and his path from former jailed gangster to philanthropist-vigilante. And yes, folks, he likes his guns a lot.

Gerard Butler is perfectly cast as the rough and tumble Childers. Thanks to his wife, Lynn (Michelle Monaghan), Childers sheds his old ways and devotes himself to God. He volunteers for a missionary trip to Uganda to build homes for refugees, then goes to war-torn Sudan where he witnesses some of the most brutal crimes against children ever committed.

It's here that Childers finds his true calling: he realises building an orphanage isn't enough. He has to stop Joseph Kony's Lord's Resistance Army (LRA) from continuing its reign of terror. So Childers, Sudan People's Liberation Army soldier Deng (Souleymane Sy Savane), plus a small force, take the fight, with guns, to the LRA.