MovieCliches.com has a rather entertaining section on guns that I though I would mention. A few of my favorites:
In 50% of action movies made after 1988, “Teflon Coated Cop Killer Bullets” will be referred to.
The fact is that not one cop has been killed by so-called “cop killer” bullets coated with Teflon. Teflon coating a handgun bullet does not make it into some magical object that goes sailing through body armor like a hot knife through butter. At the same time, it is worth noting that many ordinary hunting rifles are capable of defeating the body armor worn by most cops.
Characters use silencers on revolvers… and it works.
One other thing I would add is that many movie “bad guys” seem to be equipped with a Desert Eagle, when in fact that pistol is not all that effective in combat due to its large size, low magazine capacity, and heavy recoil (although it is fun to own/shoot ). Also, criminals rarely use such an expensive gun, as they tend to prefer small, cheap, concealable weapons.
My thanks to Tony for pointing out this website.