Best to work your way up and acclimate, don't just copy someone's hair chest load. As well, when / if you get used to them, you need to stay on your game, stay practiced for it to be of any use.
Even in my best days, I never pushed towards the top loads with the 454. I found I didn't enjoy it much past 300gr @1600fps. (And I was shooting lots of monster 500 Linebaugh loads at the time.) Now days.... 300-320 @1400 is about the most fun I want in that area and I do that in a 5 shot 45Colt. (I should sell my 454 I guess.)
I'm not trying to dissuade you from taking the journey and mastering it. But most people who climb the mountain find there's nothing up top and come part way back down. lol