He did have some experience in the military shooting, but basically while going through a divorce he took up the Olympic pistol shooting to relieve stress. Reading between the lines I think his ex might have said he'd never amount to anything. Because, rumor has it, after he got the silver medal he was heard to say to the camera, <wife's name> I want my dog back.
Very cool. No sponsor, no "uniform", no fancy gear, and when he got done shooting he wanted to know where the smoking area was.