Over 20 Pounds Of Smokeless Gunpowder Or More Than One Pound Of Black Powder. Even if intended for use in sporting firearms, California provides felony penalties for possessing more than the stated amounts of gunpowder without special permits.
California Health and Safety Code Section 12101-12112
12102. This chapter does not apply to any possession or use of 20 pounds or less of smokeless powder, or one pound or less of black sporting powder, provided that: (a) Smokeless powder is intended only for hand loading of small arms ammunition of .75 caliber or less. (b) Black sporting powder is intended for loading of small arms or small arms ammunition of .75 caliber or less. (c) All such powder is for private use and not for resale, and, in the case of black sporting powder, there shall be no gift, delivery, or other disposition to another person. (d) The storage, use and handling of such smokeless and black powder conforms to rules, regulations, or ordinances of authorities having jurisdiction for fire prevention and suppression in the area of such storage, use, and handling of such explosives.