Curious your using CCI 200 primers which are large rifle primers. Are you using Lapua 6.5 Grendel brass (small rifle primers) or fire formed brass with large rifle primers. Varget is good powder but bulky which limits its velocity in the 6.5 Grendel. With Varget you might not be seating the bullet deep enough to get good accuracy as Ive read Scenar like to be seated off the lands. Its possible your barrel just doesnt like this bullet/powder combination. You might have not hit on the right node for that powder charge. Sierra list a maximum charge of 27.7 grains of Varget with a 123 grain SMK with Winchester small rifle primers in their 24 universal receiver in the 6.5 Grendel.
Also Id double check to make sure the scope and mount are tight. Id also make sure the gas block is not hitting the hand guard and the gas tube is properly aligned. As a last resort you might try shooting the barrel with no muzzle device (FH, Brake or Suppressor).
Also Id double check to make sure the scope and mount are tight. Id also make sure the gas block is not hitting the hand guard and the gas tube is properly aligned. As a last resort you might try shooting the barrel with no muzzle device (FH, Brake or Suppressor).