I assume your talking about the heirloom rings from WoD naval mission board, but yeah failed multiple times on those myself. Took 4 trys on the caster version alone, somewhere around 98% + each. If i remember right I got the agi/melee dps first try. I dunno what the 3rd ring is myself.So..... finally got heirloom ring from ship missions..... discover there's actually 3... what a waste of heirloom upgrade items to try and use them all. So I'm working on mission for a second. Second time 98% chance mission fucking failed. Fucking horseshit. WTF is this a hairbrained schemes engine. (Notorious seemingly false %'s in their games)
I only have luck with mounts myself, ask Kurn or the rest of WoW FoH lol. Aside from years of trying to get the Onyxia mount, I just stumble over the rest of the so called rare mounts lol.