"In the first Bond movie 'Dr No' the armourer from Q branch, Major Boothroyd is seen issuing 007 with his now legendary Walther PPK which replaces his much loved Beretta.
This immediate change to Bond's gun was originally inspired by a letter that Ian Fleming received in the 1950's from a Mr. Geoffrey Boothroyd who was a firearms expert based in Glasgow, UK, who wrote to Fleming thus: " I like everything about your James Bond character except his deplorable taste in weapons, a .25 caliber Beretta is utterly useless as well as being a lady's gun...and not a very nice lady at that "
From one of Eric's original links.