Check the corners along the long edges for grain run out. It will for v's. Also look for places where the grain dips along the face. These will form circles or islands in the grain. If the grain is good you can probably get a 40-50#, man-tall, self bow out of it. If not, an easy way to make it shootable is to back it with hemp cord and tite-bond II glue. Varnish well to seal. Keep your tips as narrow as possible particularly if you back it. More weight at the tips really slows cast. These are great ways to practice your tillering skills. They're cheap so, if you end up with a 20#-er just buy another one and try again.
Sean