I'm shooting 225 gr SST's, but load data should be pretty much interchangeable.
I use CCI #250, Win brass, IMR 4350.
If a fellow started around 67.0 grains and worked up, you'd be fine. Expect your worked up loads to go over 70.0 grains for sure.
Note - I have two Hornady manuals, they are pretty heavily lawyerized, so I would not worry about working up a load that exceed's their manuals, as long as you know what you are doing. Their .375 RUM data, for example, shows 300 grain bullets being pushed a full 150 fps slower than Sierra's data. And I can personally confirm that Sierra's data is very close to real life. Some of Hornady's data is straight up retarded.....