Police Supt. Garry McCarthy said the tally could go considerably higher, reports CBS Station WBBM.
Pallets were still being unloaded at a Homan Square facility where the weapons were being sorted.
"I'm quite certain that if you look at some of these heavy weapons, we certainly are making a difference here, just by getting these guns off the street," McCarthy said at a news conference to show off some of the weapons.
The firearms ranged from an M-60 machine gun and sawed-off shotguns to pen-like "zip" guns that can fire a lethal round.
Of the more than 5,500 weapons, about 700 turned out to be BB-guns or replicas, McCarthy said.
During the gun turn-in Saturday, dubbed "Don't Kill a Dream, Save a Life," Chicagoans could turn in firearms, no questions asked, at churches to get $100 gift cards for each firearm.
BB-guns and replicas were worth $10 cards.
Some locations ran out of gift cards, and had to give people IOUs.
This year's gun turn-in appeared to be one of the more successful. By comparison, the tally in 2010 was 3,900 weapons, including 600 BB-guns or replicas.
Critics say the firearms police collect through the turn-in event by and large aren't the most dangerous kinds, and may even be decades old and non-functioning.
But McCarthy says any gun is welcome.
All weapons collected Saturday will be destroyed.
The collection comes as Chicago is drawing attention for gun-related violence. More than a dozen people were wounded this weekend, and a 14-year-old boy was fatally shot Friday night.
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