I used to have this recurring dream of being shot in the back. Here is what it supposedly means from meaning-of-dream.net:
Gun This is a dream of distress. Hearing the sound of a gun, denotes loss of employment, and bad management to proprietors of establishments. If you shoot a person with a gun, you will fall into dishonor. If you are shot, you will be annoyed by evil persons, and perhaps suffer an acute illness. For a woman to dream of shooting, forecasts for her a quarreling and disagreeable reputation connected with sensations. For a married woman, unhappiness through other women.