As another poster noted, this is a confidence problem. I used to have dreams where the gun malfunctioned very similar to what has been described. Loose slides, bullets falling out the barrels etc..Then I started spending more time at the range and Guns started working in my dreams just like real life.
My last gun dream was where I had went back to my hometown and for some reason went into an old apartment building that I used to live in and was attacked by a guy. I shot him in my dream two times and it was loud and he fell down fast. Then the rest of the dream I was running trying to distance myself from the area and was very worried about being caught by the po-lice.
In my dream the shooting was justified, yet I felt the need to run. I suppose I don't have confidence in the police? lol.
Go to the range more and watch your dreams change.