Onslaught help needed

Hey all
I really need to get Isla Innocentes finished up on hardcore for onslaught, but whenever I create a session only 3 people join, and one usually bails out. They are the last achievements I need to finish this game. Can anyone help me?

I need 'em too. Send me a message when you've set up a session. Earliest I can join is Monday, so preferably set-up the session sometime next week :)

Anyone still need to do the onslaught modes on hardcore?

Add me on xbox live, i have one other friend for onslaught