MAGOOCH. The biggest pistol I've shot is a Ruger Red khawk 480 ruger. I didn't find it or the 44 mag uncomfortable. I really liked the 480 and could hit very well with it.
As for that big rifle, yes, I'd like to try it, even though I probably wouldn't want to try twice.
Years ago a guy brought a 458 Win mag to my Uncles place to shoot. He brought 4 rds, He, my cousin, and Uncle fired it, the 4th rd sits on the mantle to this day, none of them wanted it. POWDERMAN.