Sorry, but the "can't hand your hunting rifle to a buddy while crossing a fence" in California is fake news.
Laws are laws. I guess they can be interpreted differently but I know a lot of people that don't want to test the water with an over zealous DA. I'm sure they would love a volunteer to test the water if you know anyone.
The law states that You can't "loan" a friend a gun without going through a background check and the required 10 day wait.
▪ Assembly Bill 1511, by Assemblyman Miguel Santiago, D-Los Angeles, requiring that the infrequent loans of a firearm be made only to family members.
The people of the State of California do enact as follows:
SECTION 1. Section 27880 of the Penal Code is amended to read:
27880. Section 27545 does not apply to the loan of a firearm if all of the following requirements are satisfied:
(a) The loan is to a spouse, registered domestic partner, or any of the following relations, whether by consanguinity, adoption, or step relation:
(1) Parent.
(2) Child.
(3) Sibling.
(4) Grandparent.
(5) Grandchild.
(b) The loan is infrequent, as defined in Section 16730.
(c) The loan is for any lawful purpose.
(d) The loan does not exceed 30 days in duration.
(e) Until January 1, 2015, if the firearm is a handgun, the individual being loaned the firearm shall have a valid handgun safety certificate. Commencing January 1, 2015, for any firearm, the individual being loaned the firearm shall have a valid firearm safety certificate, except that in the case of a handgun, an unexpired handgun safety certificate may be used.
(f) If the firearm being loaned is a handgun, the handgun is registered to the person making the loan pursuant to Section 11106.