Two men have been jailed for running what is thought to be the UK's first fully functioning gun factory on a Sussex industrial estate.
Greg Akehurst, of no fixed address, and Kyle Wood, of Littlehampton, both pleaded guilty at Kingston Crown Court to conspiring to sell or supply guns .
Akehurst was jailed for 18 years and Wood for 11 and a half years.
During the trial, the court heard police found parts that could have been made into more than 100 weapons.
Jurors heard guns from the factory had been sold to London criminals and linked to eight crime scenes including two attempted murders.
A third man - described by the judge as "the principal of this extremely serious criminal enterprise" - Mark Kinman, 63, pleaded guilty to the manufacture of the firearms, but died last year.
Sentencing, Judge Susan Tapping said the operation was "of the gravest possible seriousness".
She said: "Creating firearms like this had only one objective and that was to be sold to criminal customers who wished to use them with live ammunition.
"That must have been obvious to anyone involved with Kinman."
After the hearing, NCA deputy director for investigations Chris Farrimond said: "It is the first time that a fully-functioning firearms factory creating firearms from scratch has been discovered, to our knowledge, in the UK.
"It was producing handguns, copies of a Browning pistol, from absolute scratch - from the nuts and bolts and producing fully functioning lethal firearms at the other end of it, with the bullets to go with it."
The NCA raided the factory unit last August on the Diplocks estate where the business had been advertised as a gearbox repair firm.
Duncan MacGregor, a civil engineer based in the neighbouring unit who knew Kinman, described his shock when he found out about the gun-manufacturing operation.
He said Kinman would show him items he had made he assumed were for a valve, but he later realised were gun components.
When he discovered Kinman had been manufacturing guns, he said: "First of all I was really stunned, but then when I thought back... I thought yes, the whole thing fits together."