I jumped the gun and got a secured card before my discharge. Iv been discharged for about a month now and im sitting in the low 600s, my EX 8 score hit 635 this morning. Up over 100 points from Nov.
You are around where I was when I was dc'ed, and immediately apped for and received Cap1 Plat (not secured) and Disco (secured). Check my rebuilding thread if you want more details, but I think you're safe to check prequal for at least disco. I would hold off on Cap1 for at least 6mo, personally since they were IIB, but they are somewhat forgiving. Look into a local CU, they may be open to you. Check the BK friendly cards thread for more. MANY congrats, and best of luck!