But police said no one should fret if they didn't make it to Saturday's buy-back because others are planned for the near future.
A huge crowd of hundreds of people flocked to the special buy-back program, creating a traffic jam in downtown Seattle as people eager to exchange their weapons for gift cards made their way to the drop-off site under Interstate 5.
KOMO News reporter Mark Miller, at the scene, said several hundred gun owners showed up to turn in their weapons and receive the gift certificates in return.
The massive turnout clogged traffic on Sixth Avenue and on an I-5 off-ramp leading to the buy-back area, located in a parking lot underneath the freeway between James and Cherry streets.
Scalpers offering cash for guns held up signs on surrounding streets, trying to tempt gun owners before they reached the official drop-off point.
The buy-back originally was scheduled to continue through 3 p.m. But at 11:45 a.m., police were forced to turn away anyone who wasn't already in line as they started running low on gift cards.
Participants received a gift card worth up to $100 for each handgun, rifle or shotgun turned in. Assault weapons could be worth twice as much. And additional gift cards were given for high-capacity magazines that come with the guns.
The objective of the buy-back is to reduce gun violence.
"If we can prevent just one child, one innocent bystander, from being the victim of a random accident or the target of an unstable person, it will be well worth our time and effort," says King County Executive Dow Constantine.
But not everyone is convinced the tactic will work - they say criminals with guns are in no rush to turn them in. And in fact, statistics show a previous effort in Seattle failed to prevent shootings.
The last time a buy-back program was held in Seattle - in 1992 - about 1,100 weapons were turned in. But in the six months that followed, the average number of firearms-related homicides increased. The mean number of firearms-related assaults in Seattle also increased, as did the mean number of robberies with guns. Even the average number of accidental shooting deaths more than doubled, according to data in a government journal.
Most of the weapons turned in Saturday were rifles - although some were old or no longer operational. But there one or two assault weapons. The most unusual weapon turned in was a military surface-to-air missile launcher, a single-use military device that had already been fired and was no longer functional. The owner turned it in and received a gift card.
David Daily, a gun owner who came to the buy-back, said he turned in two rifles because he has inherited several guns over the past couple of years and has no need for so many. He wants to make sure none of the weapons wind up in the wrong hands.
"For me this is the short way to know that the guns I don't want are safely disposed of," he says. "I would never want one of my guns to be stolen or sold to a private dealer and end up in the hands of a criminal."
Once the guns are collected, police plan to check serial numbers to see if any are stolen. If so, they will not contact the person who turned in the weapon. Instead, they will contact the gun's registered owner and see if that person wants their firearm returned to them or destroyed.
Nearly $120,000 was raised to buy back the weapons and ammunition by the Seattle Police Foundation, nonprofits, the University of Washington Medical Center, private businesses such as Amazon.
A program supported by Seahawks head coach Pete Carroll, known as "A Better Seattle," also donated $10,000 to back the effort to get weapons off the streets.