Speaking at ACT Policing's Mitchell warehouse, deputy chief police officer Mark Walters said the industrial unit would save time.

"Up until now the processes and the practices involved in the destruction and the disposal of those items have been very time consuming but also required our members here to maintain some very specialist skills," Mr Walters said.

"The equipment that has been installed here will allow ACT Policing to destroy in 10 minutes what has generally taken one officer one day to destroy."

Mr Walters said a large number of firearms from the gun amnesty were slated for destruction in the shredder.

Before the introduction of the unit, custom built for ACT Policing, officers would have to cut down weapons to render them useless before burying them securely.

Sergeant Garry Noble, who originally proposed the idea after meeting with NSW Police, said previously it was important to bury seized items.

The lengthy process would involve officers digging a large site, burying the items, filming their burial and then marking the site on GPS before covering it in general waste.

Mr Noble explained part of the reason for this was to cover up police forensic methodology.

"There's other things that might have police markings on them or some sort of confidentiality around them that we actually bury," Mr Noble said.

The segreant said the time difference using the shredder to destroy firearms was massive, allowing officers to destroy items and securely dispose of them in general waste.

Money for the shredder was originally set aside two years ago in the ACT government's 2015-16 budget, costing about $600,000 plus $60,000 for installation costs.

Some of the items disposed of on Wednesday included rifles, pistols and other firearms. The shredder would lso be used to destorydrugs and drug making equipment.

ACT Police Minister Mick Gentleman said the display was a reminder of some of the criminal activity in the capital.

"There are some things here that you would normally see on a television show," Mr Gentleman said.

Mr Gentleman said the shredder would also be used by the Australian Federal Police.

The items are fed into the shredder via conveyor belt, which sits above the floor of the police warehouse. The shredded material falls out the bottom of the machine into a dumpster below.