A teenager ordered a handgun and ammunition online which were “designed to cause maximum damage”, a court has heard.
Jurors were shown the weapon Kyle Davies allegedly ordered from the United States along with five rounds of expanding bullets.
The Glock 17 pistol was fully operational, Gloucester Crown Court was told.
Mr Davies, 18, from Gloucester, denies weapons and ammunition charges.
Prosecutor Anna Vigars QC said the gun and bullets were “designed to cause maximum damage”.
Jurors were also told one of Mr Davies’ memory sticks contained details about making explosives and obtaining a UK firearms licence.
Other material found by investigators included a terror manifesto by mass murderer Anders Breivik about his Islamophobic beliefs and advice on “using terror to wake up the masses”, the court heard.
An online search, made five days before Mr Davies was arrested on 20 June 2018, showed a photo of the two Columbine school shooters, the jury was told.
Under questioning from the defence, DS Daniel Bickford confirmed some of the seized books and material found on a laptop and mobile phones were “freely available” online.
Mr Davies denies two counts of attempting to possess a Glock 17 pistol and five rounds of 9mm ammunition with intent to endanger life.
The trial continues.