Jim Barr was the son of a police officer who was killed and as a result took it upon himself to fight crime. He was rejected from the police for physical reasons, but got a job in ballistics. Like many characters of the time, he used chemistry to develop powers for himself; in his case greater muscle mass and brain power using his 'crime cure'. He also invented a Gravity Regulator Helmet (which was bullet shaped and gave him his name), which allowed him to fly and deflect bullets. His first case involved capturing a gangster in his hideout.