I will say this again. H110 and W296 are EXACTLY the same powder. Made by the Winchester owned company Primex I think it's named. Formulation is the same. Both Winchester and Hodgdon have said this on more than one occasion.
The differences in them are ONLY the normal lot to lot variations any manufacturer has. Why are there different loads in the same company's manuals for them? Different lots of powder, different lots and maybe brands of primers, different lots of brass and perhaps days, weeks, or even months of difference in the timing of the testing.
You're kidding yourself if you think you're finding a real world difference. If you wish to believe different be my guest. Matters not to me.