Re: hornady vs nosler
IMR and H4895 are very similar, as are IMR and H4350. In both of these examples, you can usually interchange the data at the starting loads. The top loads will likely be different by some degree, and that's why we work our loads up slowly, watching for pressure signs as we go. If you've got data using precisely the same components you are, that's always the prefered way to go, but that's not always an option, I know.
The one exception to be aware of here in the IMR and H versions, are the two 4831s. IMR4831 is significantly faster than H4831, and these tow require totally different data. Not interchangeable, despite the the similar nomenclature.
Hope that helps!