Detective Chief Inspector Stuart Spencer, who led the investigation, said Dwight Halliday has been a key figure in an organised crime group that is involved in the supply of Class A drugs in the Chapeltown area and beyond.
He said the latest convictions reflect the serious penalties criminals in the city face over their involvement in gun crime.
Last month three men were jailed for a minimum of 33 years each for the murder of Raheem Wilks.
The officer said: “His murder, at just nineteen years of age, was a very stark illustration of the human tragedy that results from the criminal use of firearms on our streets.
“The organised supply of drugs and the violence that goes with it cause understandable concern in our communities and cannot be tolerated.
“I want to reassure people that we will continue to use every available tactic to proactively target and take action against those who are involved in these offences.”
“Weapons like this have only one deadly purpose and we can reasonably assume it was being supplied to Liburd to be used in crime. The timely interventions of the police took that weapon off the streets before it could be used.
“Halliday and Liburd were arrested during a targeted police operation that came in response to a series of firearms discharges and other incidents linked to a turf war between criminal groups in the area which came to a head in the summer of 2016.
“The bad character evidence admitted to the court and our own intelligence picture shows that Halliday was someone who was very much at the heart of these events.”