A former U.S. Marine was arrested and charged Wednesday for allegedly possessing several military-issued guns and ammunition in Brooklyn on Tuesday afternoon, police said.

A witness on a Brooklyn bus called police to report a man with a gun. When police arrived 27-year-old Christopher Palumbo had gotten off the bus and allegedly gone down in to the R train station a 86th Street and Fourth Avenue.

Police said Palumbo, who lives in Chelsea, was arrested on the platform allegedly holding a duffle bag with the butt of a large gun sticking out.

Palumbo was charged with grand larceny and criminal possession of stolen property, police said. Palumbo had several weapons and other items that were military issued and he did not have permission for, police said.

His loot allegedly included a silver, unloaded 12-gauge semi-automatic shotgun, 44 12-gauge shells, 22 empty machine-gun magazines, a machete, two military radios, a military-issued laser, and a U.S. Marine Corp uniform.

Police said Palumbo had been honorably discharged from the military, but the exact details surrounding his service were unclear. He was awaiting arraignment yesterday in Brooklyn Criminal Court and could not be reached for comment.