Short Stories with Tragic Endings

I am standing at an unfamiliar staircase in what is supposed to be my house.
I am with my family and a guy I do not know comes up with a gun. I pull out a
gun as well and essentially start having a shootout with him. We start out in the
hall way then he runs down the steps. I follow and we are in some sort of
basement. I see him and start shooting, I am using an airsoft gun and so is he.
I chase him around the basement for a while and my clip runs out. I don't really
reload it or anything I just cock back the slide and it seems to have a full mag.
Every now and then a lever pops out of the gun, like a lever action pump, and I
have to fiddle around with the gun for a few seconds to get it back in working order.
Eventually, I somehow manage to get the other guy's gun and I chase him out. I
then start after my brother for some reason and we start fighting. We go around the
basement for a while and I then come to the corner I was at before and notice I only
have one gun. I think, "Where did I put that?". I look for it briefly but then abandon
my search and go after my brother again. After a while I see him and apparently he
had found my other gun. We exchange fire for a while then the dream ends