Intratec TEC-9 , TEC-DC9 , KG-99 or AB-10 is a blowback-operated semi-automatic pistol . It was developed by Intratec , an American subsidiary of the Swedish firearms manufacturer Interdynamic AB . Introduced in 1985 , the TEC-9 was made of inexpensive molded polymers and a mixture of stamped and milled steel parts , and the simple design of the gun made it easy to repair and modify . The TEC-9 developed a negative reputation for its association with organized crime and mass shootings in the 1990s , most notably used during the Columbine High School massacre by Dylan Klebold . However , it was a commercial success , and over 250,000 were sold . Interdynamic AB , a Swedish firearms manufacturer based in Stockholm , designed the Interdynamic MP-9 , intended as an inexpensive 9 mm submachine gun based on the Carl Gustav M/45 for military applications . Interdynamic did not find a government buyer , so the weapon was taken to the United States domestic market as an open-bolt semi-automatic pistol , but the design was deemed too easy to convert to an automatic weapon . Due to this , the Bureau of Alcohol , Tobacco , Firearms and Explosives ( ATF ) forced Interdynamic to redesign the firearm into a closed-bolt system , which was harder to convert to automatic weapon . This variant was called the KG-99 , and was popularized when it made frequent appearances on the popular television show '' Miami Vice '' , where it was legally converted to full auto by Title II manufacturers . The KG-9 and KG-99 have an open-end upper receiver tube where the bolt , recoil springs , and buffer plate are held in place by the plastic/polymer lower receiver frame . This design only allows for 115 grain 9 mm ammunition , and if a heavier grain ammunition or hot loads are used , the plastic lower receiver will fail or crack , rendering the firearm unusable . Later versions of the TEC-9 and AB-10 had a threaded upper receiver tube at the rear and a screw-on end cap to contain the bolt , recoil spring , and buffer plate even if removed from the lower receiver , solving the problem of lower receiver failure when using hot ammo
Columbine High School massacre
Columbine High School massacre
TEC-9