U.S. District Judge Alan S. Gold would not immediately approve the deal, saying he will decide whether to accept it later. Gold said he was concerned by the size of Wong's arsenal and set no immediate sentencing date.
Wong faces a possible maximum penalty of five years behind bars.
All the guns were purchased legally and Wong intended to resell them at profit, said Wong's attorney, David Rothman. He said Wong needs mental and anger management counseling, not more prison time. Wong has been held without bond since his April arrest.
"Calin understands that because of what he did, people were afraid," Rothman said. "He does not pose a danger."
The FBI said authorities were alerted by someone in Oregon after Wong made threats in an Internet chat room frequented by gun enthusiasts known as AR15.com.
Writing under the screen name "thehumanabc," Wong repeatedly brought up the Virginia Tech massacre and the name of the shooter, Seung-Hui Cho, who took his own life after the rampage on the Virginia campus left 32 people dead.
"I'm soon to the point to re-enact the whole event," Wong wrote, according to an FBI transcript. "This may not seem to be a threat to you but I'm sure others don't want to see it occur again. I feel there is no choice out of this other than what cho did."
A few days later, police searched the home Wong shared with his family in Homestead, south of Miami, and found four AK-47s, a sniper rifle and scope, seven handguns, 132 ammunition magazines and about 7,000 ammunition rounds.
Wong told police he had sent about 20 threats over the Internet during the past year, including a plan to harm someone by "putting a bomb on him," according to the FBI. There was no evidence Wong ever went beyond chat room comments to plan any attacks.