Not to mention significant (and more importantly) consistent expansion. Granted, if you need a bigger bullet than even an expanded tok round (I think it was around .5") then you'll need a bigger bullet. If not for the lack of bullet development (because everyone was distracted by cheap surplus and developing the 5.7x28), the tok would be as effective as the 327 Federal Magnum (and not limited to 6 shots)
Tok: 85g JHP 1700ft/sec, 4.75" barrel
100g JHP 1874ft/sec, 5.75" barrel
At any rate, the tok is well within the class of "effective" SD rounds, it just needs someone to bother developing its potential (which mainly involves designing guns chambered for it)
"I don't believe that the men of the distant past were any wiser than we are today. But it does seem that their science and technology were able to accomplish much grander things."
-- Alex Rosewater