Still have yet to get that achievement, and it's bothering me I'll be on for another hour or so. So send me a request, my gamertag is G1Destron By the way, I don't use mics cause I always blast music while I play. So if that bothers ya, I'm sorry.
Seeing how you said "achievement," I'm going to assume you're playing on the XBOX 360. Is that correct?
If you can get on tomorrow, I can probably get you to 15, I have done it solo before haha, I'll be on from 8am to 4pm est.