BD mastery is easy to reach in Pro 5ª and unblock Scope but very vey hard to reach in Experth 4ª for unblock Gold Weapons, anyway if you wanna do a mastery very very fast I advise you to following this steps about mastery bug. https://www.mpgh.net/forum/showthread.php?t=1086638
Rememember that HP hack was detected but bug mastery still working, do it wihout HP hack.
#This address still working after several maintenence.