Lucky Gunner Labs has put together an accessible exegesis of the sidearm favored by Rick Grimes in The Walking Dead. Here’s part of it:
It’s an inevitable truth– for some, ineluctable– that creative work related to zombies is likely to involve weapons and firearms. But how much detail ought one to give when it comes to guns and ammunition? How far down the wormhole of chrome-lined barrels and articulating-link piston action differentials should an artist go?
I have the sense that sins of omission may be venial, but sins of inaccuracy are straight-up Cardinal. This is as true of firearms as it is of anything else.
For example, I love the spreadsheet at the bottom of this clever blog entry by Joe McKinney about mistakes writers make when they’re writing about law enforcement. (I can imagine being moved to make this after reading zombie story after zombie story in which someone is “elected Chief of Police” or “appointed Sheriff by the mayor” or whatever.)

Getting the details right about things like firearms or police– things that most folks have a cursory knowledge of, but some people have incredibly hyperspecific knowledge of– is like paying your bills on time; there’s no reward for doing it, there are just punishments for not doing it.
But I also think you have to watch out for the other side of the coin. I’ve read a few zombie stories– all of them were, not-coincidentally, horrible– where the authors clearly expected a carnal appreciation for firearms to be the driving force that kept his/her readers turning pages (as opposed to, say, compelling characters doing interesting things). I am not entirely unsysmpathetic to this pitfall. I understand the impulse. I’ve just learned to restrain it. (To wit, I’m a drummer and I love drums and cymbals. My last zombie novel featured a drummer as one of my three main characters. I could write 5,000 words in my sleep on the history of ride cymbals, Avedis Zildjian’s influence on classical music, or the evolution of die-cast snare drum hoops. I find that stuff fascinating. Know who doesn’t? 99.99% of zombie novel readers.)

I am writing for other people. I must surrender to this fact. I am not only writing for me. And while other people might have deep-running appreciations of drums or cymbals (or handguns or police procedure), most probably don’t.
At the end of the day, your technical details must be right, but people aren’t reading for the technical details. Remember that. They are reading because you’ve just sidled up to the bar and said “Okay everybody, listen up. I’ve got a good one.”
Oh yeah? Lay it on us.
no details is a better alternative to getting it wrong. Of course doing the research and getting it right is the write thing to do.