and purposes, they're working on screwing you.
San Francisco Police Code § 613.10:
In addition to all other requirements and conditions stated in this Article, each license [to sell firearms or ammunition] shall be subject to all of the following conditions, the breach of any of which shall be sufficient cause for revocation of the license by the Chief of Police: ...
(g) The licensee shall not sell, lease or otherwise transfer to any person any ammunition that:
(1) Serves no sporting purpose;
(2) Is designed to expand upon impact and utilize the jacket, shot or materials embedded within the jacket or shot to project or disperse barbs or other objects that are intended to increase the damage to a human body or other target (including, but not limited to, Winchester Black Talon, Speer Gold Dot, Federal Hydra-Shok, Hornady XTP, Eldorado Starfire, Hollow Point Ammunition and Remington Golden Sabre ammunition; or
(3) Is designed to fragment upon impact (including, but not limited to, Black Rhino bullets and Glaser Safety Slugs).
So the ammo the police are issued isn't allowed to the peasants because those On High have decided that self-defense-suitable ammo isn't 'sporting' and shouldn't be allowed.