Maybe it is by U.S. standards, but it's still as large number as it ever has been. Even before any restrictions handgun ownership, as a conventional item of domestic equipment for the defence of person or property, was never widespread in Britain. Britons have only been interested in guns for two purposees, sport and vermin control.The guns suitable for these purposes - shotguns and various classes of rifle - were the only kinds of gun widely owned: and since they've never been banned, they remain so (particularly with the growing popularity of countryside shooting sports). By contrast handgun ownership was always very small - sold mostly to army officers at a time (up to WW1) when they were still required to provide their own personal weapons, or to men going to work abroad, especially in the wilder reaches of the Empire. The number of legally-owned handguns which had to be surrendered after the post-Dunblane ban was therefore tiny by U.S. standards - some few tens of thousands, as I remember. The notion that Britons were suddenly 'disarmed' in their millions is a bit of a myth.
Actually, it’s vermin control that I’m concerned about... of the two-legged variety.