5. Protective shield or device

Where a tool is a direct acting tool, it shall have a protective shield or device attached to its muzzle end in such a manner —

as to effectively arrest the escape of any stray projectile and any other object or particle liberated by the discharge of the tool; and

that the outer edge of the shield or device is not at any point closer to the centre of the muzzle end of the barrel than a distance of 50 millimetres, except where the tool is used in the circumstances described in regulation 23.