Talk:Mastery Rank/@comment-113.255.9.96-20130416034452/@comment-8231897-20130418174612

If you look at your profile in game, it'll list all the warframes and weapons you have used. This includes the levels you have achieved and already gotten mastery points for.

You need to get past this lvl for new mastery points. But like the previous commenter mentioned, some weapons need a minimum lvl to start getting you mastery points.