Try .200. I ran some numbers in my Oehler Ballistic Explorer and the poor BC's for little bullets really doesn't have a great impact on their down range performance. .2 will be close enough for what you need. That bullet will probably have multiple BC's depending on velocity. As it slows down, the BC drops from the effect of the HP. So it may start out at .25 at the muzzle and end up at .15 at 500m.
