I'm glad you asked this question as I have been contemplating H4198 for my 303 Brits with paper patch. I've been using H4227 and have a spare can of it but the slower 4198 sounds like a better option.
So 4198 works in the hornet? Good to know. Mine gets Lil'Gun under jacketed's and it's no slouch (55gr @ 2740 fps!) I'm wanting to try cast in it again.