Based on your initial results:
44.5 and 45.0 show a total standard deviation of 24.7 and an extreme spread of 56 fps, point of impact was identical. 45.0 group would have landed inside the 44.5 group.
I would try 44.5, 44.8, 45.0, 45.2. most likely your accuracy node will be 44.8, since any...