8.The effect of this is that the Part applies to air weapons capable of a muzzle energy equal to or lower than 12 foot pounds (ft/lb), or 6 ft/lb for an air pistol (approximately 16.27 joules and 8.13 joules respectively). Air weapons above these thresholds – or those that come within section 5(1) of the 1968 Act, for example by being disguised as another object, or designed or adapted to use a self-contained gas cartridge system – will continue to require to be held on a Firearms Certificate issued under the 1968 Act. Note that section 48 of the Firearms (Amendment) Act 1997 provides that any reference to an air rifle, air pistol or air gun in the Firearms Acts 1968 to 1997 includes a reference to any such rifle, pistol or gun which is powered by compressed carbon dioxide and therefore such weapons also fall to be licensed by the Part.