Finding a place in a normal SoO raid

So I have been playing WoW for a little while now, maybe a little over a year and have only just started getting into the fun that is raids.

It started because of the legendary quest-line requires you to go into raids to retrieve item drops from bosses. After I completed that I saw to reason why I shouldn't keep raiding for better gear, as my gear was pretty much on level with the flex raid drops it was time to start up normals.

Now here is my problem, there are always people asking for groups etc but a good 90% of the time they are asking for people with the achievement Ahead of the Curve. To be able to get this achievement you must Defeat Garrosh Hellscream on 10-Player Normal difficulty, how can I get this is no one is letting me into the raids without it?

I keep getting better gear via the timeless isle Ordos and Celestials and now have a iLvl of 555. Yet there are few willing to take me on because I do not have this achievement.

Is there anything I can do to better my chances to get into normal SoO raids? The only thing I can think of is try to get into a raiding guild but I seem to always join guilds that say they are raiding weekly but never do.