Lots going wrong there...put the walnut in the core n osage on the belly...IF you just have to have walnut as a belly use maple,ash etc(one of the lesser overpowering Whitewood's for backing),and then you have to go longer and much much wider than what you have....trying to use walnut as a belly in lam bows is a waste of time n materials IMO....I'd grind off the walnut n glue on some osage to save that if that's what ya wanna do