Hi Gabel:
I've actually not made a target like I described earlier. Just trying to come up w/ a design that's easier to come by than the traditional 3' diameter cut-off. Seems like that's why this thread began.
I do appreciate your comments and experience.
I tend to think my design would hold up pretty well actually. I envision mine made out of planks or beams at least 4" thick and 4-5 feet long. 8x8s would be best. Gluing them together like a giant cutting board would make them act as one solid slab, but w/out the warping issues. And the longer the better to resist splitting.
I do agree that it would be harder to stick the axe than in an end grain target. Maybe use pine. Just kicking around some ideas.