Informations For Mastery Hacks! Definitely Working for All Weapons Create Bunker Defense Room and press insert, after insert you may now start your game. Kill bunker defense soldier and weapon mastery will pop up of ranking of your guns. But at this point Don't Leave The Game. Continue Kill them. every soldier will count in your mastery. for those who said not working, because that you see your ranking mastery pop up and you leave your game.