Not exactly a surprise, but Public Enemies isn’t one of the most historically accurate movies ever made. From Massad Ayoob.

That said, the historical accuracies disappoint.  The film opens with Melvin Purvis chasing Pretty Boy Floyd through an apple orchard. Floyd shoots at him (one-handed at one point!) with a Thompson submachine gun, and Purvis then single-handedly kills him with one shot from a European bolt-action hunting rifle (admittedly correct for the period.) However, history shows that this happened many weeks after Dillinger was killed; Floyd was armed with a pair of Colt pistols, one of which was converted to full auto; it was a cornfield, not an orchard; and while Purvis did indeed empty his snub-nose .38 Colt Detective Special at the fleeing Pretty Boy, it is believed to have been a rifle in the hands of one of the many other lawmen firing at the fugitive that ended Floyd’s life.

On the bright side, however, it looks like Johnny Depp’s one of the good guys when it comes to guns. From Yahoo News, via The Firearm Blog.