As Professional Hunters we do not often get the chance to shoot Cape Buffalo ourselves, therefore most of our bullet tests are done (with clients permission) on animals that are recently deceased.
Below we tested Oregon Trails 430gr Trueshot hardcast lead bullets on a Cape Buffalo bull. The shot was fired into the heaviest and hardest part of the shoulder - much as you would on a live cape buffalo from 25 yards - a typical distance on these great beasts.
The results are remarkable given the poor reputation the 45/70 Government has with large African game. There was perfect penetration through the heavy shoulder bone on BOTH sides which means it also traveled through the entire body cavity and vitals.
Without a doubt, the 45/70 Government in Lever action form is a potent carry gun as long as you shoot quality weight specific bullets. To be sure, to get the weight you need for good penetration at the slower 45/70 government speeds, hardcast lead is the way to go!