As a commercially available product? None that I know of.
Back when the 10mm forum was going, I do beleive there were a few special order group purchases of them, when we were shooting/talking the .224 BOZ etc. But I don't know if any of that information survived the many purges/server updates we've had.
If you're really interested in it, your best bet would be to contact a sabot maker, and see what it would cost for a custom run.
"If there must be trouble, let it be in my day, that my children may have peace"