Arms Export Control Act basically outlaws shipping firearms and firearm parts in excess of $100 to be illegal unless a export license is obtained. This defines shipping from the USA. You may also be held responsible under French law also.
This means while it maybe ok to ship a non-title 1 part such as a magazine because "value" is under $100, French law on the receiving end may prohibit.
Also, never trust free legal advice on the internet. Do your own homework as you are ultimately responsible if you have to bring "the man" into your life.