Re: Shipping mags to California.
As stated above it is 100% legal. Yes, the law makers of CA really made a difference with the "hi cap" mag laws!
You can rebuild your worn out "hi cap" mags with NEW parts....EVERY part. And there is no stipulation on a 20, 30, 100, etc., magazine. Because CA law says anything over 10 rounds is a "hi cap" mag.
So you worn out 20rd GI mag can rebuilt into a new 30rd Pmag.
BUT....unless you have a registered "assualt rifle", or a featurless rifle (Valquartsen is one, M1A,etc.) or bolt gun....you can not use them.
But for folks like myself who travel to OR, NV, AZ,etc., we take our mags with us and use them there.
Gotta love CA gun laws......