If it needs wacking, use a baton or a rock. Not your knife! Ka-Bar's are robust, (I own one before anyone asks) but not that robust.
One thing that I am seeing this post that I don't like, is the idea of commiting yourself to just a knife(s). That's the sort of macho moronisum that survivalists come out with.
I consider a small folding saw is for shelter building etc as being at least as important as a knife. In fact, of the two, I would grab the saw first. I can improvise an edge from flint etc if I have to.