So all these auctions for magazines are going on.  If someone in say CA wins the auction is it up to the shipper to know if the magazine is prohibited?    What law has the seller broken if he ships the item to a ban state?  Why would the seller have to know what states ban said item?  Seller isn't possessing in ban state, buyer is.  

Now slow down and read that again.  I'm not asking if its legal to possess the mag in a ban area.  I'm asking why the seller has a duty to know if a legal item is prohibited from the buyer.  

If I ship a standard cap magazine to a ban state what can that state do about it other than take it from the buyer, and buyer has to deal with the consequences of not knowing his local/state laws.  

Not the sellers problem............

Ship them as repair parts disassembled if you are worried.

Here if you are LEO you can own any mags you want. Also if it is pre ban it is good to go for anyone.

I would say since that spectrum is so wide that shipping with a disclaimer should absolve you of responsibility.

Still though, if word gets out that "this guy on ebay shipped me a Pmag" you might open up a can of worms for yourself.

before i sell to ban states.

I ask questions in said state HomeTown Forum.

Never failed.

It's a state law.  If you aren't in their jurisdiction, you can't violate their laws.  It's up the receiver.

Having said that, I won't knowingly help someone violate the law.

Preban as in the 94 federal AW ban?   So the mag has to be pre 94 or does your state have another preban date?

The USPS doesn't own mail - as soon as you hand it off it is the property of the receiver. Hence, it's not your problem.