Jordan Kelly, 18, was jailed for six years after pleading guilty to possession of a firearm with intent to cause fear and perverting the cause of justice.
The 12-year-old boy was shot on March 10 2020 outside the Northfield Hall Community Centre, suffering facial injuries.
Two others were jailed for assisting Kelly to evade justice - John Foggo, 40, was jailed for four years whilst Sarah Nixon, 37, was given an 18-month suspended sentence.
DCI Vanessa Rolfe of the Homicide and Major Enquiry Team, who led the enquiry, said: "The shooting of this 12-year-old was an appalling act which could very easily resulted in him losing his life.
"He did suffer facial injuries which required lengthy hospital treatment, and I am pleased to have seen Kelly admit his role in what took place and be jailed for a number of years.
"The convictions of Foggo and Nixon should serve as a warning that attempting to help someone evade justice has consequences and authorities will prosecute those who engage in this activity."