I am called crazy as a loon so forgive me!
I will forever insist that 1300 to 1400 fps range is the best for a hard flat nose boolit for hunting, anywhere else and the boolit needs some expansion and since my best shooting is with a harder boolit I have no need for more speed.
I feel the .454 is a step up from the Colt because a decent boolit can be shot faster and at say, 1350 fps, it will do anything and outstrips the .44 and the Colt. If you want to go full pressure and velocity, it really does better with a good bullet.
The problem comes in because the .454 has a slower twist and too heavy a boolit needs shot fast so you will need some expansion unless you find accuracy below 1400 fps. Most cylinders are short so a bullet needs seated deep once weight gets too high.
Even a .44 with a lighter boolit shot too fast is not as good as a heavier one at 1350 and the caliber has a weight limit. The Colt with a heavy boolit is kind of slow, kills OK but recovery is slower on deer, it has a velocity limit.
I would stay with 335 to 350 gr in the .454. In the end, there is nothing it can't do as long as you tailor the boolit/bullet for the velocity and animals hunted.
Boolit weight is not the final answer and it is not weight alone in the larger calibers. It has a lot to do with boolit length for a given weight and stability. Going to a very long boolit in a smaller caliber presents stability problems, like the 405 gr in the .44 or the crazy 700 gr in the .500, they don't work! Shoot only what is accurate.
BUT, the .475 and .500 JRH, both with the right boolit at the same velocity of around 1350 fps with a hard cast, are stunning on game, shock to them needs to be seen.
Go larger like a .460 or .500 S&W and you just open another can of worms, they are overboard.
Nothing on earth can withstand a .454 if you shoot it as intended and choose your bullet.