RE: 45-70 or 450 marlin
This will be my 4th season hunting with the .450 Marlin. I have 8 deer and counting, best of which is 115 9 pointer. I have used factory loads the previous years, but this year I'm reloading some 300 grain Nosler Partitions with H322. I should be get about 2000 fps at the muzzle of the 18.5" barrel. That should be plenty.
I can only say that I truly love this gun for whitetails, given the way I hunt them in the thick places from ground blinds and low (15ft or less) ladders. Of course, it also helps to have the Reddot mounted scout style to enhance my enjoyment. That makes it quick pointing and quick shooting and allows me extra seconds to judge the animal. The last whitetail I shot was 20 yards away in thick pines and the gun performed flawlessly.
Yeah, you could do the same thing with the .45-70, but it's an old boring cartridge. I wanted something new and also something not many people have. This fits the bill for me, but you'll have to decide.