I quess I can't test it on a cape buffalo but I wouldn't bet against a 45-70 with 350 or 400 Grain Barnes X bullets. When spring gets here I am going to test some for Penetration and expansion. Boxes of wet news papers are not real scientific but gives a good comparision test between calibers. Barnes has a couple newer X bullets for the 45-70. I have been interested in the old 45-70 for many years and have shot it a lot with both Black powdes and smokless. Sorry about getting off track on the other post but sometimes when a stone wall and a brick wall come together , its best to give it a rest. I have my opinion on the 45-70 based on a heck of a lot of shooting. I know its capabilities and limitaions and have lived with them for years. I am happy to share that info but have no intentions of starting a program to get a 45-70 in every gun case in the country. I do believe in getting a bigger gun if needed. Although I may not agree on just when that need arises.