Thanks, all, for the comments. I'm quite pleased with the score, given the politically incorrect nature of the shot which I'm sure put some people off.
I think most people got the point of the gun barrel being the focal point. People who have had the experience of being at gunpoint frequently say the black hole of the barrel looked quite big. Unfortunately I had to have way too much light on the subject to get the DOF where I wanted it.
My toungue's not out, by the way. It just looks that way with the mouth open in a primal scream.
I ruined my voice and shot $1500 worth of cameras trying to get this. Perhaps I should have unloaded the pistol first.