WBCS-TV, New York, said an array of antique rifles, dueling pistols and shotguns were displayed Saturday at Stamford's Plaza Hotel.
Organizers of the event said the show was about collectibles and history, not violence.
But more than 50 demonstrators were on site, and said the event hit too close to home. A few protesters cited a newspaper ad for the event that appeared on the same page as an article about Sandy Hook Elementary students.
"The way it was in the paper really upset me and it's not even a month since it happened," demonstrator Linda Ferguson-Clap said.
Organizers argued the school shooting was a result of mental health issues, not the guns.
They also said that every buyer is required to undergo a background check.