Terence Carvell was arrested in June this year after police raided his property in Milton of Campsie, East Dunbartonshire.
Officers discovered three AK-47s assault rifles in his loft, a revolver and thousands of rounds of ammunition.
The 56-year-old admitted four contraventions of the Firearms Act when he appeared at the High Court in Glasgow.
Carvell tried to avoid a minimum five-year jail term claiming he thought the weapons had been deactivated.
But, Lord Bracadale yesterday said he could not find "exceptional circumstances" for Carvell to avoid prison.
Carvell showed no emotion as he was lead hand-cuffed to start his five year sentence.
Police had initially searched Carvell's home in connection with an unrelated probe.
Officers found a large haul of legal weapons, including 45 air pistols, 24 air rifles, 11 replica firearms, 10 deactivated guns and an antique gun.
But, three live-firing AK-47 Kalashnikovs were also discovered stashed in the loft along with a revolver.
A total of 2162 live cartridges of 104 different calibres were also seized as well as several hundred blank rounds.
Among the ammunition were 30 Chinese cartridges for use with the three AK 47s.
Carvell claimed the assault rifles – which can fire 10 rounds a seconds – were for a wall display.
But, they were found unmounted and had been treated with anti-rust spray.
The mortgage broker said he bought the AK-47s at a gun fair in Nottingham 20 years ago.
The revolver had allegedly been bought from a man in Falkirk for £80, but Carvell thought it was deactivated.
He also described his house as a "gun museum".
Carvell told the court: "My interest is not in live guns – my interest is having them on walls.
"I would not have bought them if I knew that they were working."