A Queensland man is in hospital with a head injury after reportedly hitting a bullet with a hammer early this morning.

Paramedics were called to a home southwest of Brisbane at 5am after reports he had struck a bullet with a hammer.

The man, aged in his 40s, suffered a head injury but was otherwise stable, alert and conscious when paramedics arrived.

He was taken to hospital in a stable condition.

Police say they are yet to confirm the circumstances surrounding what happened or whether a bullet was involved.