What a fine hunting rifle! I love the warmth of the walnut - nicely finished.
.60 cal is indeed a great calibre for a hunting rifle. My old jaeger has a .60 cal 1:66 twist Don Getz barrel on it, and it likes 86 gr. grains FFg, .595" ball and .022" patch. It has radiused rifling with narrow lands, and loads and cleans easily.
Mike's a great builder.