Spiritual Meaning:
The symbolism here reverts to a basic attribute – that of overt masculinity and a strong degree of aggression. Such an attribute can be a positively spiritual one in that Truth is incontrovertible and has to be dealt with.
Psychological / Emotional Perspective:
It will depend on the other circumstances in the dream how we interpret the use of a gun. We may be using it to protect those things we feel are important to us. Particularly in today’s climate of criminal culture, a gun can be seen as a badge of honour and in dreams may signify arrogance and power.
Everyday Material Aspects:
When under pressure in waking life, the gun in dreams can signify a particularly aggressive action and the result of that aggression. Obviously it can also signify both the actual sexual act and the result.
Gender / Specific Meanings:
If a woman is firing a gun she is aware of the masculine, aggressive side of her personality. If she is being shot at she perhaps feels threatened by overt signs of aggression or sexuality. For a man to be being shot suggests conflict which may, in fact, be territorial.
You might also like to consult the entries for Injure / Injury, Shot, Wound and Weapons.