Yeah I think Ernie will leave us all in the dust on this one...
I remember when... Actually all I know was it was over 31 years ago because that's when I came to Alaska, but when I still lived in Oregon I remember walking in one one a rockchuck from a bit over a paced 400yds. It took several rounds to walk it in. That was with a factory XP-100 in 221 Fireball :-) I don't remember what the scope was but I believe it was a fixed 6x, & I had home made sandbags (old socks filled with sand). Mostly luck & his suicidal tendency to cooperate by hanging out for multiple attempts.
Never liked that gun. 10" barrel & mid grip just felt funky