I read a lot of genre fiction, and always hate it when authors pull some incredibly-stupid boner when it comes time for a gunfight. You can tell that Stephen Hunter and James Crumley, for example, are pretty well-acquainted with guns, so their few relatively esoteric mistakes can be forgiven. But old saws like "the reek of cordite" still foul up far too many writers, who mindlessly pass them along to another generation. Thomas Perry, who wrote the excellent Metzger's Dog, will stoop to employing anachronisms and exasperating absurdities (e.g., in Shadow Woman a killer uses a .308 bolt gun firing subsonic ammo out past 1000 yards -- must've been dropping 'em in like mortar rounds) if they sound kewl enough. Loren Estleman is the worst offender that comes to mind, claiming, for example, that the M16 is a cheap hunk of stamped metal. Why these rich sacks can't simply pick up the phone and call a local gun shop to do some basic fact-checking, or spend twenty bucks to acquire a basic reference work is beyond me.
An author who apparently really does his homework is William Gibson. Almost everything he writes about is based on current or projected technology (military and everything else). He's spent the time and effort to learn the difference between a RPG and a recoilless rifle, how the HK G11 works, etc., and that attention to detail shows up on every page. And he's not flashy about it like a lot of geek writers. His future worlds are chock-full of neat futuristic stuff, but he doesn't belabor it.
I love that approach. It's a natural extension of J.G. Ballard's contention that everyone is writing science fiction now. The rapid pace of technological advancement means that current works of any description would be incomprehensible to readers from a hundred years ago (maybe even fifty), unless they were also provided with a good modern dictionary and had a lot of patience.
If you're a writer who would like to avoid embarassment, or if technical documentation on guns 'n things give you wood, go to www.scholarsbookshelf.com and do a title search on "Jane's". Whenever the CIA is pondering toppling some pitiable banana republic, the first things their boffins will reach for are probably one or more of the highly-respected Jane's series of publications. They cover everything from railroad rolling stock to aerospace capabilities, and everything in between. They are excellent -- but current editions are VERY pricey, averaging over $300 retail. So take advantage of the Scholar's Bookshelf soooooper sale of items that are just a few years out of date -- while they last.
Of the available selections, I purchased: