Government to crack down on antique guns due to crime links
New laws to prevent the criminal use of antique firearms will be introduced "as soon as possible", the government said.
The National Ballistics Intelligence Service (NABIS), which advises police forces across the UK, has called for nine types of ammunition used in such guns to be made illegal.
There has been a sharp rise in the number of antique guns being seized in recent years.
NABIS said such weapons had been linked with at least four homicides.
It said gangs had increasingly used antique firearms over the past 10 years to get around the UK's strict laws restricting access to handguns.
Antique or "obsolete calibre" firearms are not covered by the same restrictions.
"Some of them are ex-military service revolvers, so they're extremely well made," Gregg Taylor, a ballistics expert with NABIS, told BBC Inside Out North West.
"If you fire one of those today, it's as good as the day it was produced."
While ammunition for antique guns is not commercially available in the UK, criminals have been able to produce it using kits bought online and often shipped from Europe, Mr Taylor said.
NABIS's head, Det Ch Supt Jo Chilton said: "You can go and buy an antique firearm for cash with no audit trail.
"As we've seen with previous cases around the UK, people can buy multiples of them and there is no requirement to report that to the police."
NABIS first identified the criminal use of antique firearms in 2010. That year 31 antique firearms were seized by police across the UK. By 2017, the last year for which figures are available, that number had risen to 85, with a total of 543 antique firearms seized over the past decade.
Last year NABIS submitted evidence to the Home Office, calling for nine different types of obsolete calibre ammunition to be made illegal.
A Home Office spokesman said: "We are strengthening firearms controls further, including those relating to antique firearms, to stop them falling into the hands of criminals.
"The Home Office has consulted on proposals that will enshrine in law a new definition of antique firearms, ensuring older weapons that could still pose a danger to the public are properly licensed and controlled.
"We are considering the responses and plan to introduce the regulations as soon as possible."
Paul Richardson, former head of Merseyside Police's Matrix Serious Organised Crime team, said he had seen the flow of antique guns on to the streets of Liverpool.
Detectives were able to establish several had been imported from France by one man, Steven Lloyd.
In that case, antique guns were bought legally online and delivered to one address while ammunition-making kits were sent to another address, Mr Richardson said.
"We know that Lloyd brought 18 (guns) in. Undoubtedly of that 18, there will still be firearms out there," Mr Richardson said.
Lloyd was one of four men arrested and jailed for firearms offences.
Gun collectors are worried changes to the laws surrounding antique firearms could have a negative affect, however.
"The main fear is a drop in value," said Ian Barclay of the Vintage Arms Association.
"There's a lot of people - their pension is basically their collection. That would be wiped out," he warned.
Watch the full story on BBC Inside Out North West on BBC One at 19:30 GMT on Monday 28 January and for 28 days afterwards on the BBC iPlayer.