Most of the shooters are armed with semi-automatic pistols, which in real life eject a spent cartridge case after every shot. However, in this movie no cases are ejected when the pistols are fired.
Several shooters are armed with single-action semiautomatic pistols. To fire this type of weapon, the hammer first needs to be cocked, either manually or by cycling the slide. However, in every scene in which these pistols are used to threaten victims, the hammers are down. This would make firing them impossible.