The old black powder .45-70-405 sure had a lot of big American bison on its conscience.

A lot depends on what rifle and load you are using. Most commercial modern +P .45-70 loadings are limited to a 2.55" OAL and pressures to work in the action of the Marlin 1895, the most popular .45-70 lever gun these days. Buffalo Bore has a load moving a 500 gr FMJ at 1625 FPS, which will do some damage. If you are going to use a Winchester 1886 or a deep-throated 1885 or Ruger No.1 and heavy bullets you can hand load longer, to about 2.85" (.45-90 length) in the '86, maybe more in the '85 and No. 1. Then you can get that same bullet moving over 300 FPS faster at the same pressure. With a 480 gr bullet loaded even hotter in the strong single shots you can reach .450 NE territory.

The Garrett controversy aside, tests by John Linebaugh and others have demonstrated time and time again that heavy, wide meplat flat-nosed bullets, at moderate, even revolver velocities, penetrate and cavitate extremely well. If anything is lacking, it's likely energy to transfer to the target. This is why I believe the .45-70 is always a great killer but not so great a one-shot stopper, at least in milder loadings. Per Ripp's comment though, if you are using a lever action the beauty is in fast follow-up shots without the gun ever leaving your shoulder. Not a bad thing when facing a charge by a moving beast with a bad attitude.

Just my $.02. Daryl S. knows a lot about loading this cartridge if he gets around to chiming in.

All the best.