I toyed with whether or not to point that out as I really don't fancy a discussion on gun laws in the two countries, attitudes to guns, rights to bear arms, or anything else that can be mentally classed as "Massive Can Of Worms"
Rightly or wrongly, if you own a gun legally in the UK - which is a long and convoluted affair getting the necessary permissions - the police can come and check on it whenever they get bored. It probably won't happen in Newcastle as they have other things to occupy their time, but it does happen in the countryside.
Carrying a gun in public is illegal, regardless of whether you own the gun legally or not.
There are of course illegal guns, but they're illegal.