I have mine in a B&C stock, action bedded. Leupold Mk4 LR/T 4.5 x 14. Best I can do at 600 is about an 8" group with M118LR and a maybe 6"+ with American eagle 150s.
I shoot it with my AAC can on it but it is about the same with or without(group size.)
This may be average for this production...