A man adapted replica Mac-10 guns in a garden shed in Berkshire.
The weapons were then distributed to criminals in London and have been linked with nine murders.
Reading Crown Court heard Wilkinson, using the name Grant Wilson, bought 90 blank-firing Mac-10s in July 2004 from a registered firearms dealer in Northolt, Middlesex.
He then began adapting the guns using hi-tech equipment in two shabby garden sheds in a paddock behind The Briars, a derelict property at Three Mile Cross, near Reading.
