Not necessarily.
If I had a cache of guns stashed somewhere, what's the deal about giving away a spare one I have among those and trading it for a 360, and using the rest to continue my crimes?
While it technically is getting guns off of the streets, in the end, it's a plan that would fall flat on its face because spare weapons could easily be traded off for the consoles while the main horde is used to continue the crime spree. It's an idea, but definitely not a foolproof one.