Quote Originally Posted by The Fenian View Post

also when it is mastered, and you didnt catch the brief notification, you can tell becauce it will have a lightened bar in the upper ish right hand corner of it's slot in the inventory.
Now i have something else secret that I have to look for.

I'm assuming you mean the slot that has the yellow tab for a new weapon that goes empty when you click on the weapon the first time?
I forgot/forget that detail from '13.