Woman’s gun backfires because the barrel was in the sand

I believe this is a movie. All I can remember is a banged up man and woman are in a dilapidated house in the desert and there are playing cards everywhere.

At the end of the movie, the woman goes to shoot another man but the barrel of her gun was stuck down in the sand it backfires and kills her.

Please help! I have looked for years off and on when this comes to my head but found nothing!