Unabashed Rigby groupie here. The Remington version does nothing for me though I know it makes sense in the action length and economy department. The Remington just has no soul to me. The Rigby gives you more leeway to stoke it up hot, if that tickles your fancy.
I use H4831SC in mine with 350 gr Barnes X. I tried some test loads with IMR 4831 and 7828 but I wanted the temperature insensitivity of the Hodgdon powder as I was developing loads at -30C to use at +30C. Over there is not the time to find out that your handload is great for polar bears but bites the big one for use in Africa.
