I would go to:

http://www.hodgdonreloading.com/data/rifle

And type in whatever cartridge you need. Then select ‘any’ for bullet and ‘IMR’ then ‘IMR7977’ for the powder.

Now you can go back to the cartridge and it will let you scroll through the available cartridges with a recipe for IMR7977. Yours might be listed, might not. But maybe there’s a case with a similar size, or something else that could be helpful.