Xtykutl

There is a trope called Chekhov's Gun that states once someone or something has made an appearance, it must become integral to the story. Another way to think of this is, if a gun makes an appearance, likely someone will be shot with it by the end of the episode or movie.

My question is, are there any examples of guns making an appearance in a TV show arc, or in a movie, but remain unused? This lack of use I imagine would illustrate the character's decision not to come heavy handed.

EDIT: I am interested only in actual guns, whether they be revolvers, rifles, shotguns, etc. Also, the reddit link below features mainly the fantasy genre. I am looking for such an occurrence in a natural world drama or similar.

What I am looking for specifically is a character revealing possession of a gun. This reveal should be shocking to the audience, as if to say, this character is suddenly dangerous, and this gun very well may change the course of action. Then, when faced with the main conflict, the character who knows of the gun implicitly makes a choice to not use the gun. (For semantics, "used" a gun means that it could have been fired or not fired (but instead brandished as a threat) and it resolved the conflict.) Maybe I should further delineate. I might be too picky here, but I'd like it if the gun is not used threateningly. (See the entry below for Marathon Man) I modified the semantics of "used" above.

I used the example below of the movie Friday with Ice Cube where he is talked out of using it. This I suppose qualifies, but fails because he did not implicitly choose on his own to forego using the gun.

This Reddit discussion has quite a few good examples, though my favourite is right near the top:

From Reddit User MrRonok:

In the first Avengers movie, near the beginning, Thor and Iron Man are fighting, and it's shown that when Thor hit Iron Man with lightning, his power jumped up to 400%, and he could do a huge super-powered shot. Similarly, when Thor hits Captain America's shield, it levels the area of the forest around them.

I fully expected this to be showing us how they would use their powers together to be more powerful as a team later in the movie. That never happened.

Though not a gun in the literal sense, it is a powerful weapon at the team's disposal that they discover, and then never use or mention again.

This scene has always bothered me for exactly the reason you were after, it was a massive Chekhov's Gun that never gets fired!

If a gun has made an appearance, has it ever gone unused?

Joss Whedon's TV series "Firefly" episode "Trash" contains an example - The Lassiter.

The original hand-held laser pistol. One of only two known to still
exist. The forerunner of all modern laser technology.

The backstory is more than a sentence worth of relating, but the gist:
A Heist is proposed - to obtain the Lassiter:

A million-square job. The big time. I was going to cut Monty and his
crew in, but you screwed that royal.

Mal and crew reluctantly take the job mistrusting Saffron's motives in proposing it.

Long story short, the Lassiter is stolen, Saffron betrays Mal and crew (As expected).

Inara is ready for the betrayal and retrievs the gun befor Saffron can get there:

INARA Looking for this?

(Saffron) looks up to see Inara perched on the wall of some nearby ruins,
beautiful as always, in her veil and bare midriff ensemble. She points
The Lassiter.

INARA Wonder if it works?

Pulls the trigger. Nothing.

Ah-well. Still worth a fortune. (as she raises a lugar)

Saffron is not shot with the Lassiter - or anything else - it being a wholesome family show and all, but fair to say the gun is central to the plot.

Saffron's immediate fate is to be locked inside a large waste bin:

SAFFRON Wait a minute, wait, you can't -- (SLAM! the lid shuts)
-- mmmf mmfff ni ffmm do hmf!

INARA You're not going to die, you big baby. The authorities will be
here in a few hours to dig you out.

It's clear that there was no intention to kill her, just leave her for a well deserved dose of justice. The Lassiter is never fired.

This might be cheating a little, but let's look to the man who invented the trope in the first place: Russian playwright Anton Chekhov.

There have been multiple film and TV adaptations of his play "The Cherry Orchard", written in 1904. At the start of Act Two, the character Charlotta enters the stage carrying a rifle. During the ensuing conversation, another character, Epikhodov, says the following:

I'm an educated man, I read various remarkable books, but I cannot understand the direction I myself want to go--whether to live or to shoot myself, as it were. So, in case, I always carry a revolver about with me. Here it is. [Shows a revolver]

Neither gun is ever fired, or even referred to again outside of that one scene. This is Chekhov's only play in which he breaks his famous rule, and the best demonstration I can think of that violations of Chekhov's Gun have been around as long as Chekhov's Gun itself.

Here's a clip from the 1981 BBC adaptation, showing Epikhodov (played here by Timothy Spall) drawing his never-fired revolver:

I could be wrong, given my old memories:

In Marathon Man, Dustin Hoffman's character has a gun (his father's Colt Commander) and plenty of reason to use it, but never fires before finally throwing it in the river.