Former Rocky Mount Police Sergeant Thomas Robertson declined to address the court before US District Judge Christopher Cooper sentenced him to seven years and three months.
Robertson will also be subject to three years of supervised release after his prison term.
Federal prosecutors had recommended eight years for Robertson, whose sentence equals that of Guy Reffitt, a Texas man who attacked the Capitol while armed with a holstered handgun.
Robertson gets credit for the 13 months he has already spent in custody. He has been jailed since Cooper ruled last year that the former police officer violated the terms of his pre-trial release by possessing firearms.
The judge said he was troubled by Robertson's conduct since his arrest - not only his stockpiling of guns but also his words advocating for violence.
After January 6, Robertson told a friend he was prepared to fight and die in a civil war and clung to baseless conspiracy theories the 2020 election was stolen from then-president Donald Trump, the judge noted.
In April, a jury convicted Robertson of attacking the Capitol to obstruct Congress from certifying Joe Biden's 2020 presidential victory.
Jurors found Robertson guilty of all six counts in his indictment, including charges he interfered with police officers at the Capitol and that he entered a restricted area with a dangerous weapon, a large wooden stick.
Robertson's lawyers said the army veteran was using the stick to help him walk because he has a limp from getting shot in the right thigh while working as a private contractor for the defence department in Afghanistan in 2011.
The judge said he agreed with jurors that Robertson went to the Capitol to interfere with the joint session of Congress on January 6.
Robertson was an "active and willing participant", not a bystander who got swept up in the crowd, Cooper said.
Robertson travelled to Washington on that morning with another off-duty Rocky Mount police officer, Jacob Fracker, and a third man, a neighbour who was not charged in the case.
Fracker was scheduled to be tried alongside Robertson before he pleaded guilty to a conspiracy charge in March and agreed to co-operate with federal authorities. He will be sentenced next week.
Prosecutors have asked Cooper to spare Fracker from a prison term and instead sentence him to six months' probation along with a period of home detention. They said Fracker's "fulsome" co-operation and trial testimony was crucial in securing convictions against Robertson.
Assistant US Attorney Elizabeth Aloi said Robertson was prepared for violence when he went to the Capitol and did a "victory lap" inside the building, where he posed for a selfie with Fracker.
"The defendant is, by all accounts, proud of his conduct on January 6," she said.
Jurors saw some of Robertson's posts on social media before and after the riot. In a Facebook post on November 7, 2020, Robertson said "being disenfranchised by fraud is my hard line".
"I've spent most of my adult life fighting a counter insurgency. (I'm) about to become part of one, and a very effective one," he wrote.
In a letter addressed to the judge, Robertson said he took full responsibility for his actions on January 6 and "any poor decisions I made".
He blamed the vitriolic content of his social media posts on a mix of stress, alcohol abuse and "submersion in deep 'rabbit holes' of election conspiracy theory".
