I do not know much about a 45/70's but when he gave me the case... if you put a handle on it you could use it for a coffee cup... I thought my 300 Win Mag shells were a bit large but I think you could drop one of them right inside the 45/70 case...
Yeah, the 45/70 is a great old cartridge that'll still lay down the thump. My father has a Ruger #1 chambered for it. With 48 gr. of Hodgdon H4198, it'll push a 300 gr bullet over 2100 fps. It'll push a 405 gr. bullet pretty darn close to 1900 fps, using Hodgdon H322. You definately feel those when you shoot'em
. Those are decently hot loads for that cartridge, but you can get'em a touch hotter than that. Remington's 405 gr. factory load is around 1400 fps, I believe.