Aaaaahhhh yes, the Big Medicine!

That round made quite a reputation with a 300 grain bullet and fairly brisk velocities.

I knqw the .45-70 does pretty good with a 300 grainer and 2K+ velocity, but with a better sectional density, the .405 should dig deeper. You have to go to a bullet weight of 380 grains with the .45-70 to equal the .405's 300 grain SD.