[Retlaw]

Originally Posted by Gordon Booth

I'd say it's a good quality air rifle. BSA do that shape of checkering on the stock and the barrel diameter doesn't look right for a full firearm.
A FAC power air rifle can make a heck of a crack!
Whatever, they shouldn't be shooting anything in a public access area and they sure as hell shouldn't be leaving it unattended!
You have their reg. number , give the photo to the police.

That is not an air rifle, the rifle in the picture is bolt action and you can see the floor plate of a 5 round magazine. Looks more like a sporterised .303 or similar calibre, .303 is a powerful cartridge, I've hit targets at 1000 yards with a .303, and the danger area is reckoned at another 5000 yards after that.