I love how the plot depends on the greed of the target being so great that he ends up stealing his own gold.

Not that the plot would work as written today (or in a TL 8+ Traveller system), since it depends on limited communications. If the Bad Guys have working cell phones or even just walkie-talkies, the jig is very likely up. Also, there's the little problem that a competent mercenary would probably check his magazine load at some point in the proceeding, with the possibility that the substitution of blanks for standard cartridges could be noticed. It's probably be better to substitute lower-powered rounds (possibly using lead-covered rubber projectiles), then put the possible targets in concealable armor . . . and then hope Bad Guy doesn't go for a coup de grace head shot "just to be sure."