apparently you can do a little a glitch to get proficiency and the mastery what you need to do is unlock level 30 to whatever weapon you trying to get but it has to be in the mddle of the mission not at the end of the mission complete briefing for example if you unlock 30 on a longsword or dualshort swords during a defense mission on wave 2 as soon as you see the achievement for pop you hit the xbox guide button and you press start and quit the game when you load the game back up that same longsword will be back to level 29 all you need to do is basically rinse and repeat the amount of time you need for the master achievement for example to get longsword i believe is 5 times so you need to hit 30 and quit the game and load it back up 5 times i hope this helps happy hunting guys