This is so true. I remember how irate I was when I realized that Rambo III insisted that a thinly mocked-up Browning was actually a DShK. That annoyed me but not nearly as much as Neo's Scorpions ejecting what looked like 5.56 casings on the floor during the lobby gun fight. Maybe necked-down brass looks sexier pinging off the floor.

But worse than all of this is what happens in movies when people are shot. People inevitably fly backwards, sometimes tens of feet. There's a nice Quora answer about this [1]. I get the need for a great action shot, but it's a thumb in the eye to everyone who actually has even a ballpark concept of kinetic energy delivery.

[1] http://www.quora.com/Guns-and-Firearms/Does-shooting-someone....