- Hey, that's mine!
- Not anymore. Give me that.

3 seconds sound clip from the Back to the Future Part III movie soundboard.

You can hear this line at 00:56:59.219 in the DVD version of the movie.

Quote context

[...]

- Sure, and that one suits you, Mr. Eastwood. It's very becoming.

- Oh, thanks.

- Hey, Frisbie. Far out.

- What was the meaning of that?

- It was right in front of him.

- Aye.

- Swing that partner halfway round, sashay back to the head of the set, all the way up to the head of the set. Now, bow to the partner. You're through!

- Hey, that's mine!

- Not anymore. Give me that.

- There he is, Buford.

- Where?

- There. Dancing with that piece of calico.

- What are you gonna do, boss?

- I figure if I bury this muzzle deep enough in his back, nobody will hear the shot.

- Careful, Buford. You ain't got but one bullet with that.

- I only need one.

[...]