Regarding what happens to confiscated firearms in SF...

many years ago, I and a group of friends went to Los Altos Rod and Gun Club to do some shooting.
On our way back to the city, his mother came up ill, so we threw everything into his trunk and he sped off to see after his mother.
The rest of us were on motorcycles, so the safest way to transport our arsenal was to use someone's car. Long story short... police pull him over in SF and when he advises them that he has firearms in the trunk, they confiscate my handgun. They're reason is that since he is not 21 years of age, he should not legally be carrying a handgun in his vehicle.

He isn't cited or charged with anything. I take about 6 weeks worth of time trying to track down my confiscated handgun. Making about 8 appearances at 850 Bryant St as well as City Hall. Eventually, I'm led downstairs at 850 Bryant (hall of justice) and given back my firearm. It comes in a nice hard plastic storage case (nicer than the cloth one it was wrapped with) as well as 3 magazines (i only had 2 at the time it was taken away).

Moral of the story, the cops pretty much do what they want with your stuff... there is a policy for firearms used in a crime to be destroyed by the city, but i've known two cops kids who had nice gun collections with some examples of dubious origin.

If they outlaw guns only cops and thugs will have them.