Citation(s) from the GunPolicy.org literature library
UNODC. 2010 ‘Value of the Global Firearms Market (Licit and Illicit).’ The Globalization of Crime: A Transnational Organized Crime Threat Assessment (TOCTA); Chapter 6, p. 129. Vienna: United Nations Office on Drugs and Crime. 1 June
The value of the documented global authorized trade in firearms has been estimated at approximately US$1.58 billion in 2006, with unrecorded but licit transactions making up another US$100 million or so. (2)
The most commonly cited estimate for the size of the illicit market is 10%-20% of the licit market, which would be about US$170 million to US$320 million per annum… (3)
(2) Small Arms Survey, 2009, Shadows of war, Geneva, Switzerland: July 2009.
(3) These estimates are only for firearms, not their parts, accessories, and ammunition. It also does not include "light weapons", such as heavy machine guns and grenades.