Supposedly it is true. However, I believe that Ruger is using the 222 Rem case (not the .223) which has a reduced neck for the .204 bullet. Ruger is originally loading this cartridge with a very light bullet (30-33gr) which should produce muzzle velocities way past 4,000 ft/sec.
This new cartridge should grow faster than the 17HMR in my opinion. After all, we all need another centerfire cartridge; don't we? :wink:
VH