A 50-year-old man caught with a cache of illegal weapons and more than 400 kilograms of ammunition in suburban Hobart has told the Chief Magistrate he is "no Rambo".

Key points: Phillip Young pleads guilty to a range of firearms offences

Phillip Young pleads guilty to a range of firearms offences Firearms and ammunition found unsecured at three properties

Firearms and ammunition found unsecured at three properties Lawyer says the collection was Young's "superannuation"

Phillip Young pleaded guilty to two counts of possessing a silencer, three of possessing an unregistered firearm, possessing body armour without a permit, three counts of failing to comply with storage requirements for ammunition and one of failing to properly store a firearm.

He entered the pleas after the charges against him were amended to remove any mention of a rocket launcher that was found at his Goodwood property in September 2013.

Young's lawyer told the court the rocket launcher had been fired and could not be reused and was part of a collection, rather than a weapon.

Chief Magistrate Michael Brett heard ammunition was found in the bedroom, lounge room, kitchen, sheds and under the house in Goodwood.

The court heard unloaded firearms were also found lying around inside the house, in outbuildings and next to ammunition under the house.

Hundreds of kilograms of ammunition found

The court was told police had also searched Young's Glenorchy business where they found a shotgun stored between the filing cabinets.

Police also found a firearm under the mattress in a caravan at his shack at Murdunna.

In all, 429.96kgs of ammunition for a range of weapons was found at Young's three addresses, none of it stored properly.

Lawyer Garth Stevens told the court his client was deeply ashamed and remorseful but that Young was a collector, not the "suburban Rambo" the media had portrayed him as.

"He's portrayed as being someone out of control, lawless ... which is a complete misrepresentation of the defendant and in fact nothing could be further from the truth," Mr Stevens said.

Defendant 'preserves Australian military history'

Young was originally also charged with three counts of trafficking in firearms.

The DPP dropped those charges 21 months after Young's arrest and without any indictment or papers ever being lodged with the Supreme Court.

Mr Stevens said Young had an interest in the Army and military history from an early age and had served time in the Army Reserves.

He said Young's collection was one of the largest in Australia and was his superannuation.

Mr Stevens presented references to the court which spoke of Young's contribution to the community and preserving Australian military history.

Chief Magistrate Brett said the issue was not Young's contribution.

"The community concern is there's all these firearms sitting there pretty reasonably accessible to anyone with an evil intention," he said.

The court heard the effect of the charges was that Young would never be able to hold a firearm's licence again - meaning his lifetime interest in firearms was over.

Chief Magistrate Brett will sentence Young next week.