Looking at Hodgens site I see IMR 4451 giving some really impressive velocity with 160gr pt's. I have typically used IMR 7828ssc for 175's and IMR4350 for everything lighter. 4451 sits right between. H4350 & IMR4350 on the burn chart.

Their data appears to give about 100fps edge to 4451. Is this believable? I know I can get the same velocity from 4350 but it is most likely at or above 61,000 psi.