Here's what I mean... Excuse an ex-architect for using dimensions, but its how I think, and I've been building enough pyramid bows here lately to know that it works. Here's my disclaimer though: Yeah, every wood is different, and you'll have some differences given grain orientation and how you work it into a bow, but if you end up with something like this, then you'll have around a 35-40 pounder with hickory. Oak is a little less. This example turned out to be 34# with a beautiful oak board. Your hickory will obviously be a tad heavier. Like I said earlier, if you want it heavier, keep the same dimensions, but cut the length to 62"