Even if he did manage to create a safe working load at whatever OAL he is using... I still don't think H110/W296 is a good choice for the application. It's too far outside of the powder's intended purpose, and he's probably just blowing half of it into the wind, unburned. ...just wasting powder.
Looking at his data (and having been on that site a few times in the past), I suspect he seated those HBWCs out pretty far. It would be very difficult to properly seat those bullets on top of that powder charge.
Titegroup will get you into the 700-800 fps range with a lower charge weight, due to its different burn characteristics. -Same performance; lower charge weight. If you stuffed 2.5-3.0 gr of Titegroup under your wadcutters, you'd get noticeably more velocity than with the same charge weight of one of the other powders listed.
Something to keep in mind:
The HBWC will need slightly different charge weights than the DEWC, to achieve the same velocities, due to the difference in internal volume of the loaded cartridge.
Before you melt your brain while trying to come up with an alternate load, give the loaded rounds a shot. You may find that 2.1 gr Titegroup provides just what you were looking for.
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