gbran said:
I know this to be true, but how is it we can buy shotshell ammo for most handgun calibers? How is this dealt with in regulations?
Because "shotshell" ammo for handgun calibers are not shotgun shells.
CA SBS laws specify shotgun shells, not handgun caliber "shotshells".
Penal Code 17180
As used in this part, "short-barreled shotgun" means any of the following:
(a) A firearm that is designed or redesigned to fire a fixed shotgun shell and has a barrel or barrels of less than 18 inches in length.
(b) A firearm that has an overall length of less than 26 inches and that is designed or redesigned to fire a fixed shotgun shell.
(c) Any weapon made from a shotgun (whether by alteration, modification, or otherwise) if that weapon, as modified, has an overall length of less than 26 inches or a barrel or barrels of less than 18 inches in length.
(d) Any device that may be readily restored to fire a fixed shotgun shell which, when so restored, is a device defined in subdivisions (a) to (c), inclusive.
(e) Any part, or combination of parts, designed and intended to convert a device into a device defined in subdivisions (a) to (c), inclusive, or any combination of parts from which a device defined in subdivisions (a) to (c), inclusive, can be readily assembled if those parts are in the possession or under the control of the same person.