Hollywood LOVES sparks! It also loves entry wounds that look like exit wounds, cars exploding for little reason, people using for cover what a .22 would penetrate, heroes rarely missing while the bad guys fire thousands of errant rounds. I also like how they massively overdo the carrying capacity of most clip fed weapons. And how they love gigantic masses of flame coming out of what should be virtually flameless guns. The amount of flame that comes out of some .223 firearms is more than those cartridges can even carry! But, as was said, they'll pay countless millions for name stars, and seemingly nothing for effects specialists. Anyone with marginal weapons knowledge sees right through these mistakes. Amazing they can't/won't fix these simple errors...but, they sell tickets, so maybe they don't care?