I haven't actually read the entire law (AB 962) as passed. However I do know that the 50 round limitation was stricken from the final version.
Remember, this only applies to ammunition predominately used in handguns (more on this in a moment).
The law, as I understand it, requires an extensive amount of information to be recorded at the time of a sale:
Commencing February 1, 2011, a vendor shall not sell or otherwise transfer ownership of any handgun ammunition without, at the time of delivery, legibly recording the following information:
(A) The date of the sale or other transaction.
(B) The purchaser’s or transferee’s driver’s license or other identification number and the state in which it was issued.
(C) The brand, type, and amount of ammunition sold or otherwise transferred.
Ch. 628 — 2 —
(D) The purchaser’s or transferee’s signature.
(E) The name of the salesperson who processed the sale or other transaction.
(F) The right thumbprint of the purchaser or transferee on the above form.
(G) The purchaser’s or transferee’s full residential address and telephone number.
(H) The purchaser’s or transferee’s date of birth.
Now add to this that "handgun Ammunition" is nowhere defined in the law. So what ammunition is handgun ammo? That's anyones guess and can be interpreted as tight or as loose as any LEO or DA might say.... Can the CA DOJ just issue guidelines? I suppose, but the law, as passed, does not give the CA DOJ that responsibility, so I think it will be left up to the individual jurisdictions.
And that's why Sheriff Clay Parker (Tehama Cnty) is suing. He doesn't know what "handgun ammo" is nor what constitutes ammo that is used predominately in handguns. -- No one does, as there are no studies available to define what ammo is used (predominately) in handguns vs. rifles.
Depending upon how you read the law, it seems to ban internet sales. So much so, that several internet companies are going to outright ban the sales of ammo to CA.
Again, depending upon how you read the law, interstate shipping may also be banned. One Federal District Judge doesn't want to touch the Commerce issue and has dismissed, as not ripe, 2 challenges to the law.