Disturbing footage showed Martin Gordon march up to his terrified relative with a pistol in Dudley, West Mids., on August 11 last year.
A spokesperson for West Midlands Police added: "Our firearms officers descended on the site and arrested Gordon less than 40 minutes after the original call.
Det Sgt Matt Nightingale, from our MCU, added: “Gordon brandished this weapon in full view of other members of the public and made no effort to conceal it.
"Following an investigation by our Major Crime Unit (MCU), Gordon, of Brierley Hill Road, Wordsley, admitted possession of a firearm.
Gordon told Wolverhampton Crown Court he bought the the gun for protection after he lost £200,000 in a robbery.
