They smell of oil. They go off accidentally far too often. Probably the most filmed act of all time, the gunfight has almost never been portrayed accurately. Hollywood has still taught us that it's slick and beautiful. It's short and ugly.
Filmmakers know nothing about it.
We never get the dump of a ton of adrenaline into the blood that necessarily accompanies the presentation of weapons. We never get the auditory exclusion, as the hearing shuts down. We never get the tunnel-vision effect, as time slows down and the world closes down almost all visual information except the gun in the hands of the man shooting at you. We never get the coarse thickness of the hands as small motor movements become impossible. We never get the brain fog as the skull overloads with blood and the IQ drops a hundred points in the firing of a single synapse.