You would be better off if this topic was placed in the regular "bows" section. It is now in the build-along section which is described as "How to articles and archives of informational threads and members build-a-long projects". Your project doesn't fit in too well. Making a build-along is too ambitious if this is gonna be your bow. That would be best to do once you've gained more knowledge and experience. You'll get a lot more replies and views by placing it in the "bows" section. A moderator can move it for you, if you want.
A Berberis log? Now that is unique! It's nothing more than a small scrub here. Never expected it to grow that big. It's in a weird plant family with no commercial timbers. I have to idea what the wood is like. You might be the first to make a bow with this species...
Berberis is mildly poisonous, so be careful with it. I haven't researched too much about it, but you might want to wear a respirator when you're sanding the wood.
A log of wood (any wood for that matter, but in this case lancewood) that is 7" diameter, should be split before it is dried. It will take five years to fully dry as is, but more importantly: since the pith is still intact in this round log, it will split horribly. If you're not sure how to process it, it's fine to leave it be for a few weeks. But the longer you leave it round, the more chance of drying checks forming and insect attacking the wood underneath the bark. Split (/saw) it at least in half, preferably in quarters or six sections.
