Mark Malone, 36, pleaded guilty to being concerned in the supply of a Class A drug and to possession of a firearm and ammunition when he appeared at Nottingham Crown Court on Monday.
Officers said "vast amounts" of cocaine and heroin were supplied and then distributed in Nottinghamshire during the OCG's large-scale operation, which ran between June 2022 and January 2023.
Det Ch Insp Mark Adas, of Nottinghamshire Police, said Malone "presented some real risk to Nottinghamshire and Derbyshire communities".
Malone, of HMP Peterborough, was taken to court following an "extensive police investigation", led by the East Midlands Special Operations Unit (EMSOU), which focused on two OCGs from Manchester and Nottinghamshire.
EMSOU said members used different mobile phones to arrange the movement, storage and sale of controlled drugs......please watch thank you............
