The English text used as a source language in an online translation recently concluded contains a word that may easily trip the unwary: "gun".
Heathrow Airport is one of the few places in England you can be sure of seeing a gun.
In the translation into Italian, many translated "gun" as "pistola". Others chose to translate it as "arma da fuoco" or simply as "arma", and a single translator as "fucile" (rifle).
Unfortunately, although "pistola" may be the translation that first comes to mind, here it is wrong. In the feedback section, I objected to this choice of words, but most commenters disagreed, pointing out dictionary entries clearly showing "pistola" as a legitimate translation for gun.
The dictionary, however, is just a tool; it is up to us to use it wisely: "gun" should be translated as "pistola" only when it means a handgun. I would have no objection if "Doc Holliday was the fastest gun in the west" was translated as "...era la pistola più veloce del West". All of us have a clear image of the wild West as a place where rough justice was meted out by Henry Fonda as Wyatt Earp in "My Darling Clementine" or by Gary Cooper as Marshall Will Kane in "High Noon" armed with a six-shot Colt 45 Peacemaker.
But the guns carried and used by security police at airports, to guard against terrorist threats are, usually, small machine guns (i.e., "mitra" or "mitragliette", in Italian), and not the pistols or revolvers dangling from the belts of policemen (and women) in most parts of the world - but not as yet, save for airports, by British bobbies. So, unless one knew for sure that British anti-terror police are limited to hand guns only (and they are not, as you can see below), the correct translation should be "armi da fuoco" or the superordinate "armi". The translation of gun with "pistola" here is a case of overtranslation: adding more detail to the translated text than is warranted by the original.
And the objection of those who justified the use of "pistole" for guns because it was one of the terms suggested by the dictionary? One, reality trumps any reference book, and, two, "cannone" also is found in the dictionary under "gun", and while British police are more heavily armed than with puny pistols, they are not (yet) issued cannons and howitzers to blast away at travelers who forgot the strict limits on carry-on liquids.
By the way, a simple image search in Google clearly shows that the British security police weapon of choice appears to be a machine gun or short automatic rifle, see for example:
Appendix
I run a short analysis of the terms chosen by the finalists for the major Romance languages and for German:
weapon firearm pistol revolver
German waffe 2 schusswaffe 3
Catalan arma 3 pistola 3
French arme à feu 5 revolver 2
Italian arma 2 arma da fuoco 1 pistola 2
Portuguese
(European) arma 5
Portuguese
(Brasilian) arma 8 revólver 1
Rumanian armă 2 armă de foc 2 pistoale 1
Spanish arma 5 arma de fuego 2
Total 27 13 6 3