Jump the powder up on them loads, 2200-2300 is far from max pressure. I would think you should be from 2500-2600fps range with the 178, and 2600-2700 for the 168. I am very interested in the results when you get a load up there.
Max pressure is supposed to be about 2500fps with the 178gr AMAX, but will have to chronograph them in warm weather. I have been shooting in <25 F temps. Curious about accuracy results myself when I pep them up.