@EDcase
The core legislation is the Firearms act, this defines what is a licenced or unlicensed firearm.
Paintball had the first problem with firearms legislation as when it arrived in the UK it ran on CO2 but legislation only allowed for 'air weapons'
In England and Wales the Home Office & police ignored this distinction and paintball was allowed, in Scotland the police kept to the word of the law in black and white and regularly raided Scottish paintball sites. The legislation was revised to allow CO2 into the air weapons definiion
Over time other things became declared illegal such as brocock airpistols because the 'bullet' assembly contained the air and projectile
The VCRA when it was just a bill gained momentum as an anti chav law. To link into 'violent crime' but to fill the gap between real illegal firearms and lookalike toys, avoiding issues with kids playing with toys that look too real and chavs posing or using lookalikes with the defence and easy availability that 'it's just a toy'
This stood on the toes of the legitimate airsoft community and the industry stood in to negotiations resulting in an additional skirmisher defence in the act.
Paintball at that time had only a very minor and quiet true 'mil sim' community, but they didn't use lookalikes at that time. It was a battle that the UKPSF couldn't win and wasn't attempted. There is no specific paintball RIF defence - but we do have some Home Office statements, one of which came in recent years following the increase of paintball lookalikes and retailers being worried is that paintball might not need to worry about the VCRA at all as it is a low powered air weapon under firearms legislation and also has past case law with regard to frangible projectiles. If that stood up in law then paintball guns are legal unclicenced firearms and therefore cannot be IFs or RIFs
In Scotland the latest air weapons legislation requiring an air gun certificate is again a chav law (Ned in Scottish) and directly goes after plinkers. In England we have plinking but they have not had bad attention from legislations (as long as they behave under existing legislation) but have quite a problem with inner city 'plinkers' shooting from tower blocks
This was a key political message in pushing the legislation
Northern Ireland have other issues with strict controls, but is also the only part of the UK where self defence can be a valid reason for owning a firearm
Other parts of the UK haven't been hit to date with more legislation on air guns/metal BB guns etc. This is dependant on how owners act, and if the irresponsible are dealt with under the existing legislation
Across the UK in principle I would welcome tidying up of all the legislation, and to a degree would be happy to have a licence or certificate (of course depending on what hoops i need to jump through and at what cost)