An update:

ErikD, yes it was Jaktdepotet. They had a few NF left in the largest calibers. Hopefully they'll get more soon.

Since my last trip to range, I've tested some more loads and think I found the ones I prefer for now.
I've had the 500gr Hrn FMJ up to 2222fps with Norma 203B.
450gr NF to 2300fps using VV N530 and 203B
Rem 405gr from 2100-2400 using N140, and Rem 300gr at low to standard .375 H&H velocities.

I think the bulk of training to get very used to the rifle, will be with the 300grainers. They are very comfortable to shoot and I can shoot much more of them.
The 405gr @ 416rem/rigby levels are great for getting used to heavier recoil. Finally some 500gr loads but those will be more sparingly (due to the recoil for now).
The NF will be my primary hunting bullets, but not sure to which velocity I'll be loading them to. If I go after Buff, it will be heavy loads. But for elk/moose I might download them some.

All in all, I am still very happy with the rifle. No real complaints.

Erik