That is for sure a 458 get the edge but if you have the choice between a hot 45-70 and a hot 450 Marlin this is a no brainer 450 all the way, and if a Cie like Steyr Mannlicher used that caliber, it is not without very good reasons... JP.
I can't, in good conscience, post what the fellow in the Browning design department told me regarding the strength of the Browning SRC 45-70. Also, he was speaking in terms of ballistics with 500 grain jacketed bullets, so I'm not sure what that converts to in terms of 400 grain ballistics, especially at the stratospheric pressures he must be talking about. Having said that, if I wanted to hot load either of the two cartridges, I think the 450 Marlin has a stronger case and would therefore be the case I would choose, but I would not use it in a Marlin 1895; it would have to be in a strong bolt gun. If we are talking lever guns, then I would go with the Browning SRC 1886 (the Miroku made Winchesters may use the same specs and alloy's but I don't know that, so that is why I would stick with the Browning at this point). If, however, we are talking about bolt guns that I wanted to stoke up just shy of exploding in my hands, then I would go with the 450 Marlin simply because it has a stronger cartridge case than the 45-70. As I mentioned before, however, I have no interest in jacking all the power I can out of cartridges; I would simply buy a bigger gun. If I wanted a steamy .458 bullet, I'd much rather get a 458 Win Mag than stoke the bejeebers out of a 450 Marlin. In my younger days, all I was interested in was power until I started wondering, what for? Now I shoot only vintage Winchesters (except for my Browning SRC), with their old-time calibers loaded to original ballistics and enjoy myself at the range and still have no problem bringing home the venison. Even at 1,350 fps I've never had a 45-70 slug stay in a deer, not even the two I took at 185 yards once.
