A bumbling bandit wound up shooting his accomplice during a botched Bronx subway mugging yesterday, a law-enforcement source said.

Randall Harvey, 20, was allegedly among eight thugs who surrounded two men, ages 17 and 20, at Hunts Point Avenue and Bruckner Boulevard at 4 a.m., the source said.

The victims fled into a nearby subway station and onto the platform of a northbound No. 6 train, the source said.

The gang caught up with them there, and one of the thugs demanded one victim’s Marmot jacket.

The victim refused, and as a goon tried to hit him over the head with a gun, the weapon fired, striking Harvey in the leg, the source said.

Harvey was busted at the scene, as was cohort Steve Boria, 16, who stayed with his wounded pal as their accomplices fled, the source said. Both men were charged with robbery.