Wednesday, August 1, 2012

What's the deal with teflon coated bullets?

During the early 1980s, there was quite a bit of controversy about teflon-coated bullets. Some news articles even went so far as to label them as "cop killers". The reader is probably thinking at this point, "Teflon? Isn't that the stuff that they coat non-stick cooking pans with? Why is that so dangerous?" This article aims to clear up the mystery.

Teflon coated bullet

Our story starts in the 1960s, when a company called KTW Inc. (named after the founders last names, Kopsch, Turcos and Ward) from Ohio was trying to develop a bullet with better penetration characteristics. Common handgun bullets which were largely made of lead, had the problem of deforming upon hitting a hard surface, such as a car door or a windshield, and became less effective after they deformed. KTW was trying to invent a better bullet for use by police departments (in fact, one of the founders, Daniel Turcos, was a police sergeant at that time and the other two founders worked in the coroner's office of the Ohio police department).

They eventually settled on a bullet design that consisted of a steel core, with an outer jacket made of hardened brass. This bullet offered much better penetration than older lead bullets, but it had a problem because of the hardened brass layer on the outside of the bullet. This hard layer did not engage the handgun's rifling very well and the friction caused the barrels to wear out prematurely. To reduce the barrel wear, the inventors coated the outside of the bullets with teflon, because teflon is very slippery and is one of the best lubricating substances known to man (the same reasons why teflon is used to coat the surfaces of non-stick pots and pans).

In 1982, NBC ran a special television report on these bullets where they argued that these bullets were a danger to police officers (many police departments had requested NBC not to run that program). After that television show, many American gun-control groups started to call these bullets as "cop killers" because they could penetrate the ballistic vests that many policemen used to wear at that time. Unfortunately, many of these reports wrongly reported that the teflon coating was the reason that these bullets had better penetration, rather than the hardened brass jacket which was the real reason. Movies and TV shows continued to spread the myth that coating ordinary bullets with teflon suddenly made them capable of piercing armor plates.

Because of the publicity, North Carolina, South Carolina, Oregon and Oklahoma have laws that make it illegal to possess teflon coated bullets, while Virginia makes it illegal to use teflon coated bullets to commit a crime.

KTW stopped producing these bullets in the 1990s and they're not encountered as much these days. However, there are other manufacturers who coat their bullets with other lubricating substances, such as molybdenum disulfide, wax, lubalox etc.


  1. This error even made it into one of the Lethal Weapon movies. I think I remember that Mel Gibson ends up shooting a bad guy through multiple layers of steel which comprise a bulldozer blade after securing a bad-guy pistol loaded with "cop killer" rounds. Uhhhh... no, sorry. Not possible.

  2. "[...]while Virginia makes it illegal to use teflon coated bullets to commit a crime."
    Isn't it always illegal to commit a crime?

    1. Perhaps I should reword that statement better. In some states (such as both Carolinas, OR, OK), it is illegal to even possess teflon coated bullets for personal use. In Virginia, it is legal to possess and shoot teflon coated bullets for personal purposes, however if they are used to commit a crime, then an extra charge gets tacked on to the list of charges against the offender.

      Hope this clears things up.

  3. Teflon coated bullets cannot penetrate body armor. Teflon was used on some types of armor piercing ammo because the hard metal cores would erode the rifling in the barrel. The teflon is used to mitigate this effect, but it does not make a bullet armor piercing. It's the hard metal core (illegal for civilians in the US) that makes the bullet armor piercing.

  4. I have tested numerous calibers against numerous types of vests, with all the results on youtube. What makes a good armor penetrating bullet is the bullet profile (shape), diameter (the smaller the better), and the construction material. The third thing- construction material- by far being the most important.

    The are commercially available rounds in 9mm, .357 magnum, .357 sig, 5.7mm, 7.62mm Tok, .30 carbine, 9x23 and 9x25 that will defeat most if not all level II vests, and some level IIIA's.

  5. This error got repeated in the second "V" mini-series. "Teflon rounds" were the only human-manufactured ammunition that could penetrate Visitor uniforms.