Cops busted a turnstile jumper yesterday — and found he was armed to the teeth with enough firepower for a mass murder.

Reggie Allen, 39, of Columbia, SC, was allegedly carrying two fully loaded weapons — a handgun in his waistband and a machine gun in a bag — as well as an ammo clip for the machine gun.

More than 30 bullets were in the guns and clip.

Allen — who sports a tattoo on his neck saying, “Me Against the World’’ — was caught at 5:25 p.m. at the busy station at 42nd Street and Eighth Avenue. He faces a variety of weapons charges.