Ok, a lot of awesome replies, and Kegan, I'm especially glad to hear from you, I've seen a lot of good posts from you regarding bows I want to shoot in the weights I want to mess about with ;-)
As far as "why 75#"; when I decided back last July that I wanted to get into this, one of the goals I set myself was some day being able to make and draw something resembling a warbow. Ideally, I'd like to get up to a 150# draw, but that's a ways off; I don't have weights, or money for a gym membership, and I'm only slowly starting to get some motivation to work out.
But shooting arrows hits me in my FUN spot, and I've found myself doing it 'til my arms are sore, so it's a really good fit for me as far as that goes.
As far as why, my previous experience with weapons comes from my time in the army reserve, I as an infantryman for 3 years, and a forward observer with a FIST team for another 3. So I'm fascinated by the ability of a given weapon to reach out and touch someone, hard, from a distance.
Now that I've seen how much fun bows in general are, and after a lot of talking to people I've met, It's very likely that I'm going to go deer hunting with a bow, if I get myself to a proficiency level that I feel good about. I've never hunted before, but I think I'd like to try it, and I'm one of those people who would eat and/or use every last bit of the deer, from the tail to the nose.
So, my current bow is just over #70 or so, I want to make my next one better, shooting for 75# or a touch more; the one after that will prolly be #80 and so on.
Red oak, well, I liked working with it on the 2 bows I've done so far, it's cheap and readily available.
I do understand that this might very well not work; but I'm curious as to what dimensions I should be going for in the attempt. Even more, I'd like to figure out HOW to get the dimensions.
What I'd really like is a program that let me plug in a bow type, draw length, and draw weight, and then spit out some numbers like "It has to be 8 foot long, 5 inches wide, and made out of balsa", for example.
This ended up being a super long post; if you make it this far, thank you!