A Swindon man, 21, has been found guilty of shooting into a stationary car in Pinehurst, leaving a man with shoulder injuries.
Aaron Gittins, from Kingswood Avenue, was convicted of grievous bodily harm with intent after two men were shot at in the gang-related crime last January.
A 16-year-old, who cannot be named for legal reasons, admitted the same charge at Bristol Crown Court.
Both were remanded to be sentenced at the same court later this month.
Jade Turley, aged 19 from Spruce Court and 22-year-old Karvin Dhillon from Swindon Road had already pleaded guilty to conspiracy to commit serious assault at earlier hearings.
They were also remanded and will be sentenced alongside Gittins and the 16-year-old.
Det Ch Insp Sean Memory said: "Incidents like this are extremely rare in Swindon and Wiltshire and the victim was very fortunate that his injuries were not more serious."