Crimebusters (1976)

Original title: Poliziotti violenti

Major Paolo Altieri of the Paratroopers Corps foils the kidnapping of child, but becomes the victim himself of a violent assault by the bandits. He realises that the criminals have used an experimental machine gun that's used only in his own Corps. Altieri begins to take part in police raids on criminal activities, and ultimately discovers a conspiracy to overthrow the democratic government.