The possession of firearms and ammunition in Great Britain is regulated mainly by the Firearms Acts 1968 (as amended). You'll find guidance, good practice on firearms law, and forms for applying for approvals under the law.
Firearms law: guidance to the police is a comprehensive piece of guidance intended to assist consistency of practice between police forces and to encourage an informed understanding among firearms users of the considerations involved. This is the most recent version - 2002.
The 2011 leaflet 'Air weapons: a brief guide to safety' contains information on the safe handling and storage of air weapons, the different types of air weapons and air weapons and the law.
Approval of rifle and muzzle-loading pistol clubs explains what approval means and how clubs can apply for it. It also explains the criteria and conditions which they must meet in order to obtain approval and remain approved.
Other publications include:
air gun owners: new legislation - leaflet from 2004 provides advice on how to comply with the ban on self-contained gas cartridge weapons
deactivation of firearms - these specifications were revised in 2010
firearms and ammunition handed in during the firearms amnesty 2003 - a table outlining the types and numbers of weapons and ammunition handed over
guidance to applicants for section 5 authorisation to protect UK-registered ships - outlines the interim authorisation process on the use of armed guards on UK-registered ships.
questions and answers - interim process for section 5 authorisation for maritime armed security applications - series of frequently asked question about the process for applicants seeking authorisation under section 5
Police use of firearms
For general information for the police on the use of firearms, you need to go to the following pages on The National Archives: