hickory is an excellent wood for self bows. only issue with it is you have to get it dry under 8% is ideal. 10-12% not so good. if its down, you need to get to it quickly as whitewood starts to decompose quickly due to the large amounts of early growth in the rings. I like to split the log into quarters, rip the bark off the back, coat the ends with elmers glue (cheap) or shellac and let sit for about a month or two before splitting them again. the larger you leave the splits initially will help prevent warping during drying.