A legal loophole is allowing criminals to lawfully obtain weapons and commit gun crimes including murders, police have said.
The National Ballistics Intelligence Service (NABIS) said antique guns allegedly bought legally as ornaments were being used as live firearms.
About 100 such guns are in use by criminals nationwide, police say.
In the West Midlands alone, 31 people were treated for gunshot wounds in the last 18 months.
Martin Parker, lead forensic scientist for NABIS, said "a clear trend" for criminals to use antique weapons in crime went back to 2010, with ammunition being specially made for them.
Currently, old guns can be bought from specialist shops and online, with ammunition available on the black market.
The police want to see a registration system for owners to allow weapons to be recorded and traced.
What is an antique gun?
- There is no exact definition of what an antique gun is in the UK
- Home Office guidance for prosecutors classes certain guns made before 1939 as an antique
- Reproduction guns or pre-1939 items that have been extensively modified are not exempt
- Antique guns are exempt from firearms legislation as long as it is held as an "ornament or curiosity"
- Weapons seized by police include revolvers by Manufacture d'armes de Saint-Étienne (MAS) and Smith & Wesson
Det Ch Supt Jo Chilton, from NABIS, said 52% of antique firearms recovered had ammunition with them, meaning they could be used as weapons by criminals.
While acknowledging the concerns of collectors, who fear new laws could make it harder for them to pursue their passion, she warned that weapons from as far back as the 19th Century have been involved in recent killings and other crimes.
"It's about trying to find a balance to protect the public as well as allowing those who lawfully want to collect them to go ahead and carry on with their hobby," she said.
The West Midlands currently has the highest rate of gun crime in the UK, with 562 offences in the 12 months to April 2015.
With police raising concerns about the high gun crime rates in Birmingham, they are calling for tougher measures to stop ornamental guns falling into the wrong hands.
Ch Supt Kenny Bell, from West Midlands Police, said 25 firearms and 40 arrests have been made in Birmingham in recent months as officers try to stop the rise in gun crime.
"We are focusing and targeting our efforts on those people who are making the ammunition in order to fit those obsolete weapons, because in my mind they're as guilty and as culpable as the people who are pulling the triggers and carrying those weapons on the streets," he said.
Analysis: Peter Wilson, BBC West Midlands Special Correspondent
The problem of some criminals using antique weapons is not new but it's now got to the stage where people - including one man in Birmingham - have been murdered by someone armed with an antique.
Some of weapons made in the late 19th Century for the armies of the Tsar, Kaiser and Queen Victoria are getting into the hands of drug dealers on the streets of the West Midlands.
Police forces are finding old guns in the boots of suspects' cars but because they don't have ammunition it's claimed they are genuine collectors of antique guns.
What's worrying is that highly skilled black market engineers are also making the ammunition to a high standard for these guns.
However John Slough, a gun dealer based in Hereford, said tightening the law was the wrong way to go about tackling gun crime.
"If the police really wanted to stop shootings in this country, [they should] arrest more criminals," he said.
"What are you going to do, close them [gun shops] all down? The Queen collects antique guns."
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