More than 200 firearms, from .22 calibre pistols to a submachine gun, have been seized in what New York called the biggest seizure of illegal guns in the city's history.
Mayor Michael Bloomberg's administration hailed the undercover operation as proof its hard line on guns - and controversial stop-and-frisk police tactics - work.
"New York is the safest big city in the nation," said Bloomberg, an outspoken advocate for tougher gun laws.
"But year after year, illegal guns flow into our city from states that don't have common-sense laws that keep guns out of the hands of criminals. There is no doubt that the seizure of these guns - the largest bust in the city's history - has saved lives."
The guns originated from the states of North Carolina and South Carolina, a 12-hour drive south.
No permit is needed to buy a rifle or shotgun in either state, and South Carolina doesn't require permits for a handgun either. Sales of assault rifles in both states are unrestricted.
Among the weapons seized were a fully automatic Cobray 9mm submachine gun with 30-round high capacity magazine and three assault pistols with flash suppressors and high-capacity magazines. Also taken off the streets was a 7.62mm assault rifle manufactured by Chinese arms conglomerate Norinco.
Of the 19 people charged, three were already in custody on unrelated charges. The others were picked up in New York, North Carolina and South Carolina in a series of arrests.
Stung by the rejection of New York's controversial stop-and-frisk law last week by a federal judge who deemed it unconstitutional, Bloomberg's administration stressed how one suspect expressed jitters in a phone call picked up by a court-authorised wiretap.
"I can't take [the guns] to my house, to my side of town, 'cause I'm in Brownsville," a low-income and predominantly African-American section of Brooklyn, the suspect said. "So we got, like, whatchamacallit, stop and frisk."
The stop-and-frisk law allows New York police officers to briefly detain anyone they feel is about to commit a crime. Critics say the tactic is used excessively against young African-American and Hispanic males and yields relatively few arrests.
Bloomberg, who is winding up his third and final term as mayor of the city of 8.2 million - where police permits are required to buy or carry any kind of gun - has said New York will appeal against the court ruling.