Funny stuff, H-110/296.
In my Lyman manual, 23.5 min. and 24.5 max of H-110 over a 240 gr. JHP.
Half a grain less (min and max) for 296.

Loaded 50 at an even 24 gr. of H-110. Figured right in the middle of min and max oughtta be a good start.

After the first shot out of my 629 Classic DX, I ejected the case to have a look. Primer completely flatted.
...hmmm...
Fired 2 more. Primers flat as Kansas.
...hmmm...
Got away from those and shot up a bunch of 240 JHP's over 11 gr. of Unique. No problems.

When I got home, I grabbed my dammit aka bullet puller. 5 different times, pulled bullets and weighed the charges. Dead-nuts 24 grains.
These rounds were loaded old school with a balance scale, trickler, and Lee Hand Press, allowing total attention to detail @ every stage.

Curious.