It appears he will have to serve another four-and-a-half years behind bars - a sentence that is expected to leave the Indian film industry, the world's largest, scrambling to fill roles he was due to act in.
There had been speculation that Dutt would get probation, but Judge Pramod Kode said that though he wasn't sure Dutt possessed the guns with the intention of committing a terrorist act, merely having them "shows scant respect to the law."
“In no sense can this be said to be a minor offense,” said Kode.
Blow to film industry
Industry sources say that he has millions of dollars riding on him in films under production.
"It is a body blow to the film industry," said Bollywood director Mahesh Bhatt, who directed Dutt in the 1986 hit movie "Namm" or "Name."
Dutt, who had been out on bail for the past 12 years while the trial dragged on, looked down and listened with his hands clasped behind his back as the judge read out the sentence.
Within minutes he had been taken into custody.
His lawyer, meanwhile, motioned for a stay so he could appeal the sentence to the Supreme Court.
Dutt was convicted last November on a charge of illegal possessing three automatic rifles and a pistol, but acquitted of more serious terrorism charges relating to the bombings.
A well-known action hero who found a comic niche over the past five years, Dutt's case was closely tracked in this movie-mad nation.
A dozen people have been sentenced to death in the bombing trial, while 20 others face life sentences. More than 50 other people found guilty will serve between three and 14 years in jail.
On Tuesday, three others were sentenced to probation or prison terms ranging from two to five years on charges related to Dutt's weapons
The Mumbai bombings trial began on June 6, 1995, and has dragged on for 12 years due to delays on procedural matters and the trial's scope - 686 witnesses gave testimony filling 13,000 pages.
Dutt was able to complete pending movie projects during bail extensions over the past year.
The actor is the most high-profile among 100 people found guilty in the bombings trial, one of the world's longest-running court cases.
Police say that the serial bombings that killed 257 people were ordered by India's most wanted man, Dawood Ibrahim, to avenge the razing of a 16th-century mosque by Hindu zealots in 1992.