Just as a warning, I kind of have a gun fetish. So that means when I’m talking guns and/or my character’s fiddling around with theirs, I’ll get super specific.

Here are some helpful links so you know what I’m talking about: 

• Stupid Gun Mistakes Every Writer Makes (Well most of them. I pay attention to realism when it comes to firearms.)
• Don’t Shoot Holes in Your Credibility
• Writing Tips: Guns, Bullets And Shooting With J. Daniel Sawyer

Also, I will be factoring in proper gun safety. Bear in mind I’m not some beer-swilling redneck who waves a shotgun around willy-nilly. I grew up learning how NOT to handle a gun starting at about the age of five. My first Nerf gun was actually a practice in gun safety. But I’m rambling—the first part you need to consider is the trigger. A character who knows how to handle firearms properly WILL NEVER—I REPEAT NEVER—PUT THEIR FINGER ON IT until they actually open fire. That’s one of the basics as well as not pointing the gun at anyone or anything they don’t want to shoot at. They’ll also make sure NOT to dual-wield like Classic Lara Croft. They’ll aim the weapon much like this. Yes, I know that standing with their side to the target and holding the gun up with one hand looks cool, but it’s FAR less accurate. If anything, they’ll hit the wall behind the target they’re trying to go for.

I’m willing to answer queries, but here are the basics for you:

1. Shoving a semi-automatic pistol (like a Colt .45 or a Glock 23) into the back of your jeans is the stupidest idea one could have. HOWEVER, if your character’s like mine and they’re in the middle of a post-apocalyptic wasteland where specialized concealment holsters aren’t readily available, they may use their waistband, though using their belt would be a slightly better option. But there’s a good chance the character can find a holster they can strap to their leg instead for storing pistols.
2. No fingers on the trigger until the character is ABSOLUTELY ready to fire.
3. No pointing at anyone you don’t want to shoot at.
4. Don’t go waving it around willy-nilly, even if the gun’s possible safety is on. Not all guns have safeties, and I doubt your character would want to severely injure—or even kill—someone they care about on accident.
5. Pulling the slide back on a semi-automatic pistol only chambers the round. 
6. This would be a clip. This would be a magazine. The two terms are not interchangable. Make sure you know that.
7. This is a revolver. It does NOT use a magazine like a semi-automatic does. Instead you load a round into six empty chambers of the cylinder, which in turn revolves as you shoot each round.