Late on Wednesday evening, police and an ambulance were alerted to an address east of Eskilstuna.
According to the police, two men are said to have practiced shooting and for unknown reasons, one man was hit by a dangerous shot in the leg.
A man in his 35s was taken to hospital and it is unclear how serious the injuries are.
Police have seized weapons and ammunition and suspect the other person, a man in his 30s, of causing bodily harm.
The incident will now be investigated further through, among other things, interrogation of those involved.
The text is updated