Wooo, that's pricey!!
Well, save that brass, first of all!
Spanky, I've had great success with my .45-70 both in the field and at the range using Trapdoor level loads with both the 405 Rem JSP (they're not expensive from Midway and other sources) and 405 RNFP lead. So far the 405 Rem has gotten 2 deer and 2 bobcats (!!), and it's a hoot to shoot. You may get several recommendations on powders, but I settled on IMR 4198 for my Trapdoor loads-- I don't have my notes in front of me, but I seem to remember the charge is around 32 grains, giving me about 1350 in the 22" barrel. IMR 3031 was also very accurate, but this is a pretty low pressure round at Trapdoor levels and I got a lot of unburned powder with those huge honkin' 3031 grains... Re7 wasn't accurate in my rifle, neither was H335 or some other medium burning powders I tried. After experimenting some with crimp/no crimp and seating length, I seat the Rems to the 2nd cannelure and use a Lee Factory crimp. You don't have to crimp loads for the Handi of course, but the velocities were more consistent and the groups were tighter with the crimp.
I did load up 20 rounds of Ruger-level loads once to see how they'd do. Shot 3 of them off the bench and took the rest home and pulled the bullets. 3 was enough! No need to beat yourself half to death to kill deer with the .45-70.
The old gubmint is easy to load for, you'll enjoy this rifle! 74 bucks? Wow!
Rick