“Greater Manchester Police officers searched an area at the end of Ashley Lane.
“On July 2, officers engaged in a search in front of a property, the occupier was watching and called the defendant.
“Following an external search of the property, officers found a black Retay box that was buried under an inch of soil.
“Inside the box was a Colt revolver in its original lethal purpose, a Retay firearm as well as two bullets in a magazine, two bullets in a tissue and two shotgun cartridges.”
The revolver had been tightly wrapped in cling film and it was on the handgrip of this that Keelan was identified as a prime suspect through DNA.
Two red shotgun cartridges and 15 bullets were also found under the soil, the court heard.
He also pleaded guilty to an offence of assault occasioning actual bodily harm, in which he had attacked a man in a car park, punching him twice to the face.
He was left with a swollen eye and cut to his mouth.
Keelan was said to have no previous convictions.
There was a brief discussion with his barrister, Jane Dagnall, and the sentencing judge, who had already seen a document regarding sentencing guidelines, so no further mitigation was advanced in open court.
Sentencing, the Recorder of Manchester, Judge Nicholas Dean QC said: “The reality is, I have no choice but to impose a sentence that means passing the minimum sentence of five years imprisonment.
“Quite how you became involved in organised crime is impossible for me to say.
“That involvement led to the possession of a Colt revolver and possession of prohibited ammunition without a certificate.”
Keelan, of Wardley Avenue, was jailed for five years.
Detective Inspector Phil Kennedy, from GMP’s Serious and Organised Crime Group, said: “Monday’s sentence is another huge step in our fight on organised crime and the use of firearms across the region.