When I first started shooting the 30x46, I ordered a few hundred of the 300 savage brass from winchester and remington.  I also got a couple hundred Lapua .308 cases and formed them.  Seems like most folks are using the lapua stuff, some have the .308br brass with the small primers.  I've weighed the cases, not sure of the range but I usually sort out enough cases to make a batch of 50.  Usually, mine are sorted to +/- .2 grains on either side of the selected case weight. 

do you prefer to use the 300 savage brass over the Lapua 308?  is is a case capacity thing, case forming issue or some other reason?

I've not shot anything but the .308 brass and haven't been shooting it all that long either, so I'd love to hear more about what others are using for the shortened .308 variants.