Talk:Weapons/@comment-6552501-20130401033900

No, every weapon starts unranked, and must be leveled to 30 individually.

Your mastery rank is determined by leveling warframes, and weapons. Therefore, it's recommended you level weapons to 30 before selling them. It can be boring, and tedious, but until they do a new system with prestiging your favorite weapons(which they mentioned at some point apparently), you have to level everything to 30 to get the most bang for your buck.