I checked Nick Harveys 9th Ed and he lists IMR 4895 with a 150gn at 38 ~ 42gns so going by that info you supplied your on the low side I did look at the 06H (supposedly 4895's equivalent) info from ADI but you cannot cross reference between burn rates to any real degree.
I have used the Hornady 150gn Spire points in my No.4's and they go really well being .312" all I can say to you is to start at 38gns go up in .2's up to max till you hit the sweet spot all the while checking for pressure, I have used BR-4's and 210's and 210 Match all with good results.
So its range time till you get there the 6.5 x 55's are good shooters

I also run a file on my computer with all loads and jumps for the 12 rifles I use along with a thumb drive which I load the data onto every time I update the info on the computer usually barrel counts, scores and weather conditions