https://nra.org.uk/surrender-of-mars-and-lever-release-rifles-under-owa-2019/
Why does the UK NRA say that compensation was offered for MARs rifles? The only way they couldn't have been paid is if they missed the cutoff window or surrendered it to the police without compensation.
I do know there was a person who had an airgun that got reclassified into section 1 firearms just lose it without compensation, as the government remedy was allowing you to put the previously unclassified airgun onto a FAC but the person didn't have a FAC and no compensation was offered for it.
I recall my shooting pals b*tching about all the money they had lost. Maybe they missed the deadline?
As for the airgun, here in UK the legal limit for an airgun is 12 ft lbs m/e. It is up to the manufacturer to ensure that that figure is not exceeded using a wide variety of pellets, some of which MIGHT conceivably bust the limit. As such, FAC-level airguns are very popular among the pest control crowd, because of their quietness when used with a sound moderator and their limited range. Add to that the accessibility of uncontrolled amounts of ammunition. .22cal ammunition is controlled by the limitation imposed by the issuing authority, as detailed on your FAC. Pellets of all kinds are free from this regulation.
Sound mods for airguns are not controlled items, unlike the same for cartridge-firing weapons. In the case of acquiring ANY mod for your cartridge-firing rifle, you must apply to have one on your FAC - as such, it is counted as a firearm. I have no need of such a thing for any of my rifles, as I don't shoot game. Since we use military ranges for our .50cal shooting, we don't use mods on them - most ranges suitable for the .50cal BMG, Cheytac, Accuracy International and Barratt rifles that they have are around 4000m and remote, as befits any military range where large bans are commonplace.
Night-shooting of the one predator - the fox - is commonplace, and it behooves the pest-control shooter to use a mod. The UK is a pretty small place, and sound carries a fair way at night in the countryside hereabouts.
In UK there is no restriction on the capacity of a magazine - of any kind. However, a shotgun that can shoot only three shots can be held on the far-easier to obtain Section 2 [Shotgun] certificate - barrels must be 24" or over. Practical shotgun shooters, with their 8+ capacity mags, need a FAC for their guns. Any rifled firearm needs to be authorised by an FAC - one FAC covers all the guns and ammunition. Each new rifled firearm has to be authorised, whereas there is not limit to the number of shotguns you can have on a Section 2 certificate.
If you want to buy ANY modern-made replica of a firearm, you need an FAC.
If you want to shoot ANY genuinely antique RIFLED firearm as I do with my Sniders and Pritchett rifle, you need an FAC.
If you want to shoot ANY genuine antique smoothbore firearm - Brown Bess, Charlotteville, matchlock musket et al - you need a shotgun Certificate.
Your FAC is your authorisation to buy powder and primers, but only for reloading the ammunition that is on your FAC - in my case, small pistol for my Ruger Super Redhawk .357Mag, and large rifle for all my centrefire rifles.
Black powder and the various subs - Pyrodex, Triple 7 et al, require a Class 1 Explosives license and secure [wooden] storage , up to 25kg. The license is free .
Nothing else is.