Just a side note:
Most of my loads were developed before modern manual data was available and attempted to flatten the trajectories for semi open forest hunting which is mainly what I was doing. The Marlin's tended to show capability for velocity increases, but as many have alluded to, you paid a price in discomfort with the hotter loads and because pointed bullets were showing up in the '90's in particular, they created more interest in pushing velocities albeit, also demonstrating that the basic rifle design wasn't friendly to pushing loads excessively.
For that reason, I dropped the .45/70, stayed with the .30/30 for light use and concentrated more on the .458 Winchester and .460 Weatherby (and a bunch of .416's to be truthful) which utilized those lighter pointed bullets in a more efficient package, in a rifle designed for heavier recoil management and serious use where the .458 caliber may be intended. This certainly wasn't Australian feral culling or American deer hunting which as others have commented, doesn't require heavy loads to secure success in the field over usual brush shooting ranges where this lever rifle is more suited. This makes the above quoted loads just a part of my own history and not necessarily a recommendation on how hard you can push the 1895 design which is really a modified 336 action thinned internally to accommodate the fatter cartridge. Removing metal for design evolution does not strength the action. Something to think about, as I would tend to favor lighter loads in using a .45/70 today.
