Sandra Bullock is fuming over claims she made a Nazi-like sex tape with cheating husband Jesse James. Celebrity author Ian Halperin claimed on his Web site that the pair indulged in a taped sex act during which James was “sporting a Hitler moustache with brown hat with a swastika,” and that James might use the video as leverage in their divorce case. But Bullock told People magazine yesterday, “There is no sex tape. There never has been one, and there never will be one.” Meanwhile, witnesses tell Page Six James has “an impressive collection of weapons” at his Long Beach, Calif., motorcycle shop. Forbes writer Dirk Smillie, who interviewed James in 2007, told us, “I spotted a grenade launcher . . . There are also some fierce power tools . . . nine power hammers operated by foot pedals, including a 1940s model used by the Nazis to make wing sections for Messerschmitt” fighters. James’ lawyer, Joe Yanni, declined to comment.