Just went to the range today with my 5R with:
Lapua 167gr Moly Scenars
New Lapua Brass
Benchrest primers
43gr Varget (IIRC, not quite sure off the top of my head but that sounds right)
Seated them right on factory OAL which it loved.
It was awesome, though I wasn't going for groups so much this time as I was punching holes in pennies for fun and zeroing the rifle to where I wanted it.
the groups I did get though at 100yds had 3 rounds all touching.
I also hit a rock at around 800x as well.
Another guy gave me 3 rounds to try with Varget, winchester brass, and 175 SMKs, they also shot bang on.