Even before he got to work Friday night, a Queens transit cop busted two teens on gun charges in the Rockaways.

Sgt. Jason Jansky was driving to his precinct about 10:45 p.m. when he spotted a boy, 16, fire a gun outside the Hammel Houses near Beach 84th Street and Rockaway Beach Boulevard.

The shooter, who didn’t strike anybody, was with his 16-year-old buddy at the time.

The cop pulled over and identified himself to teens, but they took off on foot.

Jansky caught up to the duo about a block away and detained them until on-duty cops showed up.

Police recovered a gun in the bushes near the scene.

Both teens were charged with criminal possession of a weapon, reckless endangerment and tampering with physical evidence.