Quote Originally Posted by Snapshot View Post
Not true for airguns. Barrel and overall length are not part of the definition. Original power/intent is what matters. This is why it's not legal to stick a shoulder stock on a pistol and up the power to 12 ftlbs.
Do you happen to have a reference for this in the firearms act? Genuinely curious. Even what the cps say is a bit confusing.

https://www.cps.gov.uk/legal-guidance/firearms

An air weapon is defined, under section 1(3)(b) and 57(4) of the Firearms Act 1968 as:

"an air rifle, air gun or air pistol which does not fall within section 5 (1) (a) and which is not of a type declared by rules made by the Secretary of State under section 53 of the Firearms Act to be specially dangerous".