eddie:
At short ranges like you mentioned, your arrow is still going through paradox and from the sounds of things your setup might be the wrong spine. Properly spined tapered arrows will overcome paradox faster, however I think its more of a spine issue. I have made and sold breast tapered arrows and shafts for many years. The Idea behind tapering is too cause the shaft to straighten out quicker, but even tapering won't correct improper spine.
Bob