The most effective means is to keep people out of crime in the first place, and I said Czech approach, not US. If someone wants to murder you ,access to a gun is not going to be the main deciding factor, because you know , cars bombs knifes blunt objects poison and a whole manner of things exist etc. The uk does not suffer from the social or economic problems the US has, and for situations that it does hold similiarties the uk has much stronger mitigating factors, like a functioning social safety net. (Well until the tories kill it off anyway)
And also I live in Ireland. A place that uses an even stricter version of the “U.K.” (Security theatre) approach, if you want to know how well that works with determined people visit “free Derry” were police can’t even exit bullet proof cars without serious threat to themselves and the IRA frequently executes via firearms people who they deem to be drug dealers. On top of that most people who would carry these weapons for illegal offensive purposes already do. Hurls and bats are popular for criminals to use for instance, I’ve personally been beaten up with a hurl like this.
There are many “pro gun states” in the 1st world with liberal fire arms laws that don’t seem to suffer the issues plagueing the USA at all. The Czech Republic, Germany , Austria , Serbia and Switzerland are all countries that have vastly easier firearms acquisitions then the uk. It’s also with noting that the Czech Republic has conceal carry permits and is also one of europes safest countries (there isn’t a connection, the Czech Republic simply lacks the socio economic problems that push people to crime at these scales. Also notably they have been ran by left leaning social democratic governments , a coincidence?)