Available data relate to offences involving firearms (excluding air weapons) recorded between 2003-04 and 2007-08, and were published in table 2.12 of ‘Homicides, Firearm Offences and Intimate Violence 2007-08' (HOSB 02/09), which can be found online at:
http://www.homeoffice.gov.uk/rds/pdfs09/hosb0209.pdf
Firearms are taken to be involved in a crime if they are fired, used as a blunt instrument or used as a threat.
Data on arrests relating to gun crime cannot be provided by the Home Office since (a) the centrally held firearm offences database does not record detection or suspect data, and (b) offences involving firearms cannot be identified on the centrally held arrests database.