I've seen the film on Youtube of a 707 doing a barrel roll at Boeing Field piloted by a test pilot. I've heard, but not confirmed that a 747-100 also did one there during flight trials.

An AA Pilot told me he thought it would be pretty easy to do it in a 757 or 767 and that the secret is to start with the nose of the plane pointing slightly downwards (obviously from a high altitude).

Has anyone heard of a 737-xx (or other plane) successfully pulling off an intentional or unintentional barrel roll.