Usually when guns are involved in my dreams it's all good, although I do have occasional 'nightmares' where a friend/loved one was the victim of violence and I was unable to intervene because of crappy shooting on my part.
My best friend since middle school has frequently told me about a recurring dream he has involving firearms, and the gist is that he is the victim of a violent attack and he is able to draw and aim his firearm with ungodly speed and precision, but there is always one of two problems. Either the trigger pulls up to the breaking point, but then seems to gain an incredible amount of pull weight, or the trigger pull is so extraordinarily long that his earlier speed is made null. He says that every time, he KNOWS the trigger can be pulled, but he never manages it in time.
"If you carry a gun, people will call you paranoid. That's ridiculous. If I have a gun, what in the hell do I have to be paranoid for." - Clint Smith