The Association of Garda Sergeants and Inspectors (ASGI) is calling for the Uzi submachine gun to be re-issued to all detectives.
The weapon has been withdrawn from service and replaced with handguns for all units outside of Dublin.
Inspector Walter Kilcullen said the Uzi always proved a great deterrent to criminals in the past, and the death of Detective Garda Adrian Donohoe might have been prevented if he was armed with an Uzi.
"Maybe that night, if he had an Uzi submachine gun what happened mightn't have happened," he said.
Detective Donohoe, a father-of-two, was shot dead during a robbery at the Lordship Credit Union in Co Louth in January.