Crew or equipment visible
Incorrectly regarded as goofs
Cherry's gun-leg does not appear to have a function to fire and change ammo, but the leg was designed in the company of a bio-mechanical engineer that clearly has capabilities beyond a rational reality, so the fact that she doesn't need to pull triggers or activate different weapons in the gun-leg is rational, given the context and scope of the movie, along with the obvious fact that the technical functions of the device were deliberately overlooked by the filmmaker(s) to keep the action pace of the "grindhouse" film.
In the jail cell scene where Wray (Freddy Rodriguez) asks J.T. (Jeff Fahey) if he's alright, he holds his gun upside down while he fakes handing it to the guard, he then shoots the guard. He is holding the gun by the frame. The gun is a 1911 style pistol. A 1911 style pistol can only be fired by squeezing the grip safety on the back of the pistols grip. The gun would never have fired in this case. However, not all 1911 style pistols have the grip safety. More than one manufacturer has made a 1911 style pistol without the grip safety and there are plenty of people capable of pinning this feature on an original or replacing the frame for one without a grip safety.