Personally, I didn't realize the gunbarrel themes were so different from each other until I listened to them through headphones. In fact, there is this common misconception that all the gunbarrel themes from Moonraker to The Living Daylights are essentially identical, when the truth is that, while quite similar, the arrangements do have some interesting differences.
Also, if one only listens to the gunbarrel music while watching the films, one tends to overlook plenty of the little intricacies unique to each gunbarrel. So some time ago, I came up with the idea of writing a breakdown of all the gunbarrel themes, since often, in articles and forum posts on the internet, their instrumentation is described inaccurately and quite incompletely. Since I was a kid, I've always been fascinated by the gunbarrel sequences of the James Bond films, and in particular, their varying arrangements of the James Bond Theme. (Last updated on NovemUpdated links, added info on different mixes of The Man with the Golden Gun, and added info on percussion instruments in multiple gunbarrels)