You should now be able to find Berger Hunting VLD .30 cal 185g in stock. The 190g will be manufactured late this month and I think the 210 will be later in October. I have been looking for same for many months as well.
I recommend you try Retumbo powder for the 300 RUM. You will likely gain velocity and maintain good accuracy. The heavier bullet will likely be better if you intend to shoot long ranges 800+.
Of course, your gun may shoot one more accurately than another. So, try them all when you can get them.
If anyone wants to sell a box of 190's or 210's to me, I need them as well.