absurdum said:
Well the guy with the desert eagles isn't a law abiding citizen. But I'm assuming that they are not imposible to acquire in the UK (anyone see snatch?).
Remember Snatch is a movie. But your right it is not impossible to buy guns in the UK, otherwise you wouldn't have drug-dealers shooting each other in the streets, as does happen.
But it is not something most citizens would be able to do, or even think of doing, unless they were already involved in criminal activity, and most probably violent criminal activity.
So I wouldn't allow any starting character to have one, unless they were an bank-robber, drug-dealer or working for a government agency which would allow such a thing.
If he isn't a government agent then be sure to make the players life hell, whenever you feel like. For example nearly every club and many pubs in large towns will search people before they enter, if he is carrying then he will be detained. Police will probably all ready have a file on him and he might come under survielance or be raided, firearms offences are taken very seriously in this country.
If he every uses it or is even seen with it, expect the police to respond rapidly with a very heavy hand, ie rapid firearms responce unit, who will very likely shoot him dead rather than risk injury to themselves or one of the public.
Britain is a bit behind the USA in regards to 'no-lethal' weapons and so don't expect to be hit by a 'bean-bag gun' or similair they will just shoot you. They will probably feel real bad about it afterwards as it usually means they will be suspended pending an inquiry, but that doesn't mean they will hesitate.