As a gun-owning USian, I’m not particularly bothered by photos of people holding Real Guns(tm), even when they’re scantily clad models. What makes me nervous is if the model is ignorant and/or nervous about guns (or arrogant – but that gets into a political rant that I’ll leave unwritten here), and what makes me break out into a cold sweat is mixing real guns with a storyline that requires deliberate misuse. In particular, a storyline that calls for a gun to be pointed at one of the models makes me want to insist that only fake props be allowed on the set.
As for “darkly realistic” vs “Charlie’s Angels style,” I suspect that a large part of what made the “Deadly Rivals” set dark was showing the gun and the victim in the same frame. It seems that “Charlie’s Angels” very rarely did this, and when they did it was usually a standoff where both sides had guns pointed at each other. The more usual situation was to show someone pointing a gun at an off-screen target figure and then cut to a view of the target figure with the gun off-screen.
Also, the way the gun is held in “Deadly Rivals” (arm extended, finger on the trigger) does give a vibe of “I AM going to shoot you” rather than “Obey or else.”