Those velocities are doable with bullets of that weight and from the pics, pressures were right around 50kpsi.
I load 196 grain .323 Norma Oryx, flat base, round nose to 2600fps for my 8x57JS chambered rifles with 23 1/8in bbls with W760
As most here know, even present manuals only offer loads that will be safe when the larger JS (.323) bullets are fired through the "J" (.318) bore.
Europeans are expected to know the difference.
