Two Australian men needed surgery after shooting each other in the buttocks during a drinking session to see if it would hurt, police said on Wednesday.

The men, both aged 34, used an air rifle to fire at each other on Sunday. By Tuesday, both were in hospital to have pellets removed from their buttocks and legs.

"The men were sharing a few beers on Sunday evening when they thought it would be interesting to see if they shot one another with an air rifle, if it would penetrate their skin or it would hurt," a police spokesman said.

"It appears other than a bit of pain, the two men from the base of the Grampians (near Melbourne), thought they were fine.

"Two days later, both men have been admitted to hospital and require surgery to remove slug pellets from their buttocks and legs."

One of the men has been stripped of his firearms license over the incident.