Mick North, 54, lost his daughter Sophie when gunman Thomas Hamilton walked into the Dunblane Primary School gym on 13 March 1996 and opened fire.
A scheme to register every licensed rifle and shotgun user across England and Wales on one central database is being delayed by technical problems.
The new system was recommended following the tragedy, but due to technical problems will not be implemented until April 2004 - eight years later.
Dr North, who is a campaigner and member of the Gun Control Network, told BBC News Online: "It would be naive to think the database will deal with all aspects of gun crime.
"But it's one important contribution and you get the feeling if there was a strong enough will it would be up and running. This delay could cost lives."
The retired lecturer from Perthshire said the database is much smaller than other systems such as the DVLA's.
And the fresh delay has dampened his optimism about other government promises to restrict replica guns and airguns.
The National Firearms Certificate Holders Register database was recommended in the 1997 Firearms (Amendment) Act and by the official inquiry into the 1996 Dunblane massacre.
Police say it will help crime detection and prevention.
But this week's edition of Computing magazine says the register will not be placed on the Police National Computer until at least April 2004.
'Fresh approach'
It was due to begin development last month but problems integrating different forces' firearms records means the contract will be re-tendered and awarded next spring.
A Home Office spokeswoman said: "The original tender did not provide a satisfactory solution for the police service.
"A fresh approach was needed to produce a more advanced technological solution."
But campaigners have accused the government of dragging its feet.
Gill Marshall-Andrews, chairman of the Gun Control Network, told BBC News Online: "This is incomprehensible and demonstrates a lack of will in the Home Office to see this through.
"It doesn't surprise me but it's very disappointing."
She would like to see the weapons as well as the owners registered.
Opposition MPs say the government is not taking crime seriously enough.
"One has to wonder just how much of a priority it is for them," Conservative home affairs spokesman James Paice said.
"This is yet another example of the government failing to deliver on promises."
Hamilton killed 16 children and their teacher, and injured 12 other children and two teachers, before killing himself.