David Jolley, 40, of no fixed address was sentenced to life imprisonment at Preston Crown Court after he pleaded guilty to robbery and possession of a shotgun at an earlier hearing.
He was ordered to serve a minimum term of six and a half years before he will be eligible for parole.
Detectives launched an investigation into the robbery which happened on the evening of Friday November 13, 2015 when a group of three or four men wearing balaclavas forced their way into a farmhouse off a private road in Adlington, Chorley.
The occupant, a 50-year-old man, was tied up and threatened with a shotgun and a machete while the offenders made demands for money and access to the owner’s firearms.
A shotgun was discharged during the incident, although fortunately no one was hurt.
Seven firearms were taken from a gun cabinet along with some ammunition and cash.
The offenders made off in the owner’s Land Rover Discovery which was later found abandoned on Thirlmere Road, Blackrod.
Two men aged 55 and one man aged 41 were also arrested on suspicion of robbery and have been bailed pending further inquiries until May 8. A third man aged 20 was also arrested but was later released without charge. The investigation remains on-going.
Det Insp Jo Keay from South CID said: “I am pleased that Jolley has been sentenced for his part in what was a truly shocking and violent robbery.”