Reloading for the .45/70 is almost exactly like loading for the .38 special, just on a grander scale.
Straight wall (or minimal taper) cases, light case lube for the .45/70 (Same if you don’t have carbide dies for the .38), a little flare on the mouth, lots of different powders, charge weights and bullet styles-weights to choose from, and then apply a good roll crimp when the bullet is seated... and away you go.
Once you start reloading for the .45/70 you’ll find that creating loads all across the power spectrum is tons of fun, and you’ll be shooting the gun five times more often because you’re not paying 35 to 60 bucks for every box of 20
.
The GG is a great hunting tool, and it’s fun on the range, too. I’m glad to see you’re enjoying yours as much as the others who bought one do!
Stay safe!