Turn heavy ammo into vendors for perfect rolled gear or perfect rolled weapons. Having gear that fits your playstyle, chest and boots that have shotgun, sniper or fusion ammo will help a lot in pvp. Also chest with increased armor for your subclass. Gauntlets with increased melee speed and reload speed for whatever primary you use in pvp. A helmet with increased super from revives helps in trials. Also pay attention to intellect, discipline strength to get the build you want