Four of these were meant to fire blanks but had been converted to take live rounds.
Robert Bartell, from Cambridge Street, Walsall, also pleaded guilty to being in possession of 23 9mm improvised converted projectiles without a firearms certificate and a prohibited explosive cartridge bullet.
Mrs Sati Ruck, prosecuting at Wolverhampton Crown Court, said the defendant entered the pleas on the basis that the altered handguns had never left his home, he had no association with violent crime and had no intention to sell them.
The weapons cache was discovered when police executed a firearm warrant in a swoop on Bartell’s home address on November 29 last year, Judge Michael Challinor was told.
Mrs Ruck revealed that on a previous occasion the defendant had offered other firearms for sale on eBay.
She explained that further inquiries were needed to check if any of the current haul had been offered for sale or were being prepared for distribution since they were “very valuable saleable items.”
The prohibited modified firearms seized in the police raid were a Zoraki handgun, an EKO handgun, A BBM Minigap, a Kimor handgun and a sawn off shotgun, the court was told.
The judge asked that tools found at the address be examined to see if there were “elements of professionalism” in the modification of the weapons.
The case was adjourned to February 28 when it will either move to sentence or arrange a Newtown Hearing if the prosecution find grounds to oppose the basis on which the defendant entered his guilty pleas.
He was remanded in custody.