Henry big boy .45C load data

[clegger]

Hello fellow gun nuts,

I recently purchased a Henry big boy in .45C and would to load my own loads as the gunshop cowboy loads are mighty pricey $34 for 20. I also know cowboy are somewhat weak in the powder charge.
I would love to get some recepies to some hot 255g and 300g loads. I'm a big fan of big bangs and blown up pumpkins and don't give a hoot bout recoil.

How much pressure can these handle and what powder/primer mix do you recommend?

Thanks