Guide to get r3:
Make your own groups.
Seriously, you're not going to get into the large majority of ranked groups. You can argue "well they MIGHT be good" all you want, but having seen some of the crap people roll in unranked randomway - I'm betting the MAJORITY isn't.
So, make your own goups. Find out the latest gimmicky build, and shout "Group LF <builds>" don't mention rank, if they ask, tell them there's no rank req. If they press you for your rank then tell them your unranked trying to start HA. Generally most people will just join without caring though.
Second if your guild has TS/Vent, use it. If your guild doesn't I believe TS has free public servers. Vent might too, not sure.
Step 3, grind. Grind, and grind some more.
If you aren't completely terribad you'll make friends, hopefully you'll get high ranked friends who will invite you to their high ranked groups. Prove yourself there and you get more friends.
Then you might end up like me, get r3 and realize that HA really kind of sucks.