No, you do not need a FFL to sell an occasional gun. However, if you have a FFL that will sell it on a consignment basis, relieves you of a lot of headaches, and may bring a better price.
When selling, if sold to a resident of another state, you would need to ship it TO a FFL in the recipient's home state. Be sure to include a copy of your driver's license so the dealer can record it in his "bound book".
EDIT IN LIGHT OF BELOW- I am assuming this is a Norinco M-14 which is semi. LEGAL full auto military M14's are scarcer that hen's teeth, and another matter entirely.
What we have here is... failure- to communicate.
Last edited by c3shooter; 10-20-2012 at 08:26 PM.