Tyron Spence, who had just bought the weapon which his criminal past prohibited him from having, panicked when he saw a police patrol on August 17 last year.
He was at the wheel of a Peugeot 208 belonging to his "on off" partner who insisted she never leant the vehicle to him despite his claim to the contrary, a judge heard.
The 31-year-old defendant sped through red lights during a two-mile chase across the centre of Dudley, from Duncan Edwards Way and through Trindle Road and Union Street.
The hatchback clipped parked vehicles until it reached Wolverhampton Street where it careered into an unattended mobility scooter, sending it smashing through the front of David's Cave second hand shop.
David Dils, manager of the store, said after the crash: "The car mounted the pavement and crashed into the scooter which pushed it into my shop window.
"The scooter was completely written off and caused about £2,000 of damage to my window, but luckily no one was hurt. Several parked cars were also damaged in the chase."
Spence, who had neither insurance nor valid licence, continued to St James Road where he crashed into a wall and abandoned the vehicle.
The recently purchased CO2-powered revolver was left under one of the seats in a bag alongside a balaclava hood, explained Ms Caroline Harris, prosecuting.
The weapon is prohibited for five years after release to those, like the defendant, who have served jail terms between three months and three years long.
Spence gave a false identity when purchasing the pistol in Oldbury but police identified him from CCTV and he was finally arrested in November.
Mr Philip Brunt, defending, said the officers had been searching for somebody else when they made the discovery and added: "The gun, which in itself is not a prohibited weapon, had not been used in any way and nobody was injured as a result of his driving."
Spence from Gilbert Avenue, Oldbury who had previous convictions for 26 separate offences, admitted dangerous driving, failing to stop, possession of a prohibited revolver and not having a valid licence.
He was jailed and banned from driving for 15 months on release by Recorder Michelle Heeley QC.