A small, extremely fast moving round with limited expansion and will UNDOUBTABLY be listed on the pending AWB Legislation?? If you are building it to sell it off in the immediate future, I would say go for it.
If you are building it for yourself, I would seriously take a look at ammo prices and availability for the long term - I fully expect this ammo to be right up there with the .50BMG on the Left's list because of it's "Bullet Proof Vest Defeating Ability".
Personally I like the round, but it's not a practical unit, or price tag, for any of the platforms at this time.
I still might consider making a very short rifle for varmint hunting out of the caliber some day. Minimal recoil, minimal noise, flat shooting trajectory.