Are component parts of an air weapon covered?
Yes, you will need a certificate to own or acquire individual components of an air weapon. This generally means parts which are required to fire the gun. Accessories like sights or stands do not need a certificate.
They just go with the home office guidelines
DO COMPONENT PARTS OF AN AIR WEAPON FALL UNDER THE NEW LEGISLATION?
The component parts of an air weapon, and any accessory to such a weapons designed or adapted to diminish the noise caused by discharging the weapon, will fall within the remit of the new legislation and therefore, if held, will need to be certificated.
Although there is no statutory definition for the term component part, the Home Office Guidance states:
“The term “component part” may be held to include (i) The barrel, chamber, cylinder, (ii) Frame, body or receiver, (iii) Breech, block, bolt or mechanism for containing the charge at the rear of the chamber (iv) Any part of the firearm upon which the pressure caused by firing the weapon impinges directly. • Magazines, sights and furniture are not considered component parts”.
http://www.scotland.police.uk/about-...g/legislation/