I bought my 45/70 for popping pigs in heavy brush. It is often argued that a big is no harder to bring down than a deer. I disagree. There are certain anatomical concerns when shooting a pig, related to penetration. The angle used to access the boiler room becomes more critical with a light-weight bullet. My personal feeling (based on real life experiences) is that the fast, big, hard, flat-nosed bullet handles brush much better than a hyper-speed lighter, pointed projectile. It is faster-handling in brush, and faster to rechamber a round than any bolt-action I have used. And it has knockdown power that is (again IMO) far above those smaller, lighter, faster bullets. My imagination can come up with several outcomes to a blotched shot at a charging boar that would be infinitely more unappealing than anything I can think of as a result of a poorly placed shot at a deer. If I am close, but not right on the vitals, I want it to hurt! I do not want it to just piss him off.
I now use the 45/70 for deer too, as I don't like a wounded buck after dark if I can help it.
The 45/70 Gov't is powerful medicine for wild boar. When "Ol' Beulah" (45/70 Marlin 1895CB) speaks, pigs lay down. If they ever don't, but come lookin' for trouble, "Nellie" (45 LC Ruger Vaquero) is always by my side, ready and willing to have her say, even if I drop Beulah.