One of the dumbest things in America (symbolism over substance)
So let's do the math on gun buy-backs.
Wilkinsburg, PA did a gun buy-back, and only got 40 guns at about $50 each, and was disappointed because they usually get 120.
On the street, a stolen gun goes for about $50 (according to ABC and some others).
So what happened here is they spent about $2,000 + labor value (figure another $4,000), or about $150 a gun to "get them off the streets"....
Except they weren't on the streets, by the articles admission, they were safely tucked away somewhere. People were disposing of unwanted guns, which means they likely didn't have any ammo, and were harmless. Or what usually happens, is that people: (a) Steal guns (or get them with other things they sold) to sell them to cops for $50 and a dose of irony. (b) People are getting rid of their worst guns to trade up. (There are many guns that aren't worth $50... and often at the higher priced buy-backs, there are stories of people making hardware guns for $20, and selling them back for $100-150 a pop).
And how does this help?
Well, on that day, in the U.S., we made about 25,000 new guns (about 9-12M guns per year, not counting ones smuggled from other countries, or made illicitly).
There are about 5,000 cities in the U.S. (4,727) with populations greater than 5,000 people.
If every one of them netted the same amount of guns, in simultaneous buy-backs, on the same day, they would still be 5,000 guns short of that day's production. And these events are like quarterly or semi-annually.
To call gun buy-backs useless is an insult to uselessness. They reward theft. They encourage gaming the system. They waste time. They teach stupidity (that the problem is the guns, and not the criminals). And they do absolutely nothing to reduce the supply. If you had one of these every day of the year, in every major city (and you could keep the rate that high), it would still mean the total number of guns in the U.S. would increase by about 2M/year.