No. I would think it would be heavy, expensive to produce or buy, and possibly harmful to your barrel over time. Bone is composed of calcium and silcas, along with other trace minerals, all of which are hard enough to scratch the bore on the soft steel stock used for ML barrels.
When You consider how cheaply you can acquire corn meal, or " Farina ", or wasp and hornet nests, or simply buy well made OP wads to use in place of a filler, it doesn't seem very practical. And, if MLERS are anything, we are practical! :hmm: :thumbsup: