ORIGINAL: DANTHEHUNTER
The 45/70 is one of my favorites to hunt with.On deer size game a 300 grain round will plant any deer.There is plenty of factory ammo for sale and different power ranges.Remington 405 grain are some of the lower end while the buffalo bore and garrett being the upper end.(they should only be shot in a modern firearms)This question is ask all the time and to answer it very easy -- that round almost elimanated the buffalo so on deer its a snap.The 38/40 I have no experince with but I am sure you can find ammo.
I agree with Dan, the 45-70 has been used to hunt everything from whitetails to dangerous game in Africa. I use a Marlin 1895G for bear with fantastic results. There are lots of commercial loads on the market which gives us a wide range of grains to choose from. I use Garrett's for grizzly, 540 gr. hammerhead +P and it's devistating. I also use Hornady Leverevolution 325 gr. for whitetails.