I am certainly not new to archery but I have never built a self bow yet. I am limited in what is available to me, south coastal oregon. I was wondering if anyone had ever used any of the wild fruit woods for a self bow. I have quite a bit of wild plum on my place and have been slowing working a stave I cut last fall. It is shaping up nice but I worry that it will snap the first time I try to get it to full draw. Still just thinning the limbs right now, haven't started to tiller. Thanks

The wild plum should make a pretty good bow. Get the limbs bending as soon as you can but only a little at a time. Exercise the limbs after each wood removal but never pull it past the intended draw weight or draw length.
Post pics as you go along and you'll get lots of help. Its easier to tell you what's needed if we can see what you are talking about.

I guess the plum is not going to be my first choice in the future. I was just flexing the limbs a bit and had catastrophic limb failure. The limb did not split, just snapped straight across! I guess I need to get out and find some pacific yew.

No you have done something wrong. If you had reduced the plum correctly it would not have broken. Plum is top notch bow wood. Yew isn't magic!!! it has to be treated the same as any other stave.
I'd recommend buying the Traditional Bowyers Bible vol 1

I agree with Mike. Sound wood doesn't break just flexing it. Will you post pics of the break?