I don't have experience with it, but I remember reading that is roughly 80% of the recoil of the .44 mag. A little digging around the web and I saw that number and 85%. Take that for what you will, as it obviously depends on several factors (bullet weight, velocity, weight of the gun, etc.) Point being, it's a step down from a .44, but not a giant one. Find the heaviest gun you can....
As I revisit this thread, I must admit that my 180gr Hornaday SST handloads for my .300WSM really did the job on that elk. Clean through, taking out both lungs, liver , and the bottom of the heart. View attachment 49065
.257 Roberts for deer and .270 Winchester for elk, both Remingtons. Models 700 Classic, and Model 721 respectfully. And I wouldn't hesitate to take the Roberts elk hunting with some of the new bullets.
What bullet would you use in a 257 Roberts on elk? The smaller case capacity would limit your downrange energy. Shot placement would be crucial. Are there still elk hunters with that much patience? (So many people I run into during hunting seasons seem to shoot first and look later. They can be scary to be near)