Except the standard bullet weight in the .330 calibre was 250 grains.

I noticed at the SHOT Show in Melbourne that Bertram makes a 180 gr bullet in .330 so a .318 W-R now has the choice of 250 gr Woodleigh FMJs and RNSPs or 250 gr Bertram (I think) and 180 gr Bertrams.

The 180 gr Bertrams are not premium bullets but do expand the versatility of the .318 especially say for goats and pigs in Australia.

In addition to the .318 W=R being like a .330/06 as Mike says it is basically the same as a .338/06. Sometimes guys with .318's make brass from the .30-06 case I believe.