AAarrrghhh!

Few things make my blood boil faster, or cause me greater frustration, than when an otherwise competent author has one of his characters click off the safety catch of his/her revolver.

I am part-way through Stieg Larsson's 'The Girl Who Played with Fire' (brilliant, read it!) but  on p.231: "Modig ... drew her service weapon [and] clicked off the safety catch ..[later].. she still had her service revolver in her hand".

OK, people, I'm only going to say this once, so pay attention: some cows have 5 legs or 3 horns - it's not unknown, but it's very, very rare.

Webley Fosbery revolver

Some revolvers (the Webley Fosbery, one model of Mauser (both of those from around 100 years ago) and a 1960s French police-issue Smith & Wesson (dropped after police officers started getting killed through forgetting to disengage the safety) had safety catches - it's not unknown, but it's very, very rare.

The remaining 99.9% of revolvers have no safety catch, because they do not need one.

Authors, please note.