It's interesting that, by and large, this discussion splits (unsurprisingly) on national lines; Americans for - Europe against. The argument about private use of firearms will never be settled, it's just too emotive. However, there are at least a couple of facts:
1. The rate of gun crime is far lower in the UK than in the USA. Fifty crimes prevented are not worth even one person wrongfully killed.
2. The first American pilot to fly into LHR or LGW with a pistol in his bag or on his person is going to have a very nasty surprise along with a sudden introduction to a diet of porridge!