With all of the legal exposures related to selling retail ammo, trapdoor mid 1870's steel at black powder pressure loads do not shock me at all.Don't own a 45 70 but those rounds seem to be a little anemic. Maybe instead of a Grizzly bear picture, they should have put a picture of pussycat. Definitely would not use those on a Grizzly bear hunt. I know those rounds are not hunting rounds. They are paper punching rounds. But if they're cheap, why not.
If you have modern steel, roll your own. Before the Biden spike in components hit, 5 boxes of factory 45-70 cost got you into the reloading world.
Good luck finding mechanicals and components now.