agreed to stop selling teflon to individuals and companies that used it to make ammunition. Several calibers of KTW rounds were proven to penetrate ballistic vests under certain conditions. However, their inventor Kopsch said in a 1990 interview that "adding a Teflon coating to the round added 20% penetration power on metal and glass. Critics kept complaining about Teflon's ability to penetrate body armor [...] In fact, Teflon cut down on the round's ability to cut through the nylon or Kevlar of body armor." Legal status United States The federal ban on armor-piercing pistol ammunition uses only the composition of the bullet's core to determine legality. However, many individual states have legislation restricting various kinds of coating materials, for example: Alabama state law provides that "the possession or sale of brass or steel teflon-coated handgun ammunition is illegal anywhere within the State of Alabama". Hawaii state law prohibits the "manufacture, possession, sale, barter, trade, gift, transfer, or acquisition of ... any type of ammunition or any projectile component thereof coated with teflon or any other similar coating designed primarily to enhance its capability to penetrate metal or pierce protective armor." Kansas state laws states possessing, manufacturing, causing to be manufactured, selling, offering for sale, lending, purchasing or giving away any cartridge which can be fired by a handgun and which has a plastic-coated bullet that has a core of less than 60% lead by weight, whether the person knows or has reason to know that the plastic-coated bullet has a core of less than 60% lead by weight is unlawful. North Carolina state law specifically forbids persons in that state to "import, manufacture, possess, store, transport, sell, offer to sell, purchase, offer to purchase, deliver or give to another, or acquire any Teflon-coated bullet". Oklahoma – Teflon-coated bullets are illegal in Oklahoma under some circumstances. Oregon state law forbids the possession of any handgun ammunition, the bullet or projectile of which is coated with Teflon while committing or intending to commit a felony. Pennsylvania state law provides that "It is unlawful for any person to possess, use or attempt to use a KTW teflon-coated bullet or other armor-piercing ammunition while committing or attempting to commit" certain enumerated "crime[s] of violence". South Carolina state law specifically bans "ammunition or shells that are coated with polytetrafluoroethylene (Teflon)". Virginia state law specifically bans "bullets, projectiles or other types of ammunition that are: coated