A father and son who supplied criminals with deactivated guns along with "kits" to convert them into live, usable weapons, have each been jailed for seven years.
William and Mitchell Greenwood were both jailed
William Greenwood, 76, and Mitchell Greenwood, 42, from South Wingfield, Derbyshire, sold hundreds of guns.
They were found guilty in January and were sentenced at Nottingham Crown Court on Monday.
The court previously heard they ran an antiques shop in Little Eaton.
They sold legal weapons deactivated under Home Office legislation, but offered expert advice on how to convert the items into working firearms.
The court was told that during an undercover operation between 1998 and 1999, the Greenwoods sold a detective an array of sub-machine guns and pistols.
They had once joked that if he bought 10 French-made MAB handguns he would be given one free.
Jurors heard the Greenwoods also took out advertisements in gun magazines, detailing their stocks of weapons and conversion kits.
These include a barrel blank, a length of metal tube used as a gun barrel, and a reamer, a tool used to create a chamber inside the barrel.
The two men claimed they legally sold all the items and had never offered customers advice on the reactivation of the guns.
Both men denied a charge of conspiracy to convert deactivated firearms into live weapons.
Sentencing the men, Judge Alison Hampton told them: "You showed no remorse, no regret and no sense of shame for the consequences of your actions.
"You were at the head of a supply chain and without your readiness to supply those customers with criminal intentions, some of these crimes would not have been committed."
She told William, who suffers from a heart condition, and Mitchell, who has had cerebral palsy since birth, that their fragile health could not mitigate for their actions.
"You must realise that age and physical infirmity and disability cannot disguise the gravity of this crime."
She ordered both to pay £20,000 costs and made separate confiscation orders of £12,000 on each man.
Detectives mounted a £1m inquiry into the Greenwoods' trade and later confirmed that more than 3,000 weapons sold by the family may remain in the hands of criminals.