When I shoot Rock Chucks for these farmers I go at it in a different way, they want them GONE! So I get myself into position to eliminate the problem. Most of my shooting with my Custom Shop XP 223 is 150-300 yds. It's really kind of tough to get much closer than 150 yds. after the first shot anyway.
Ernie liked to start at 300 yds & go out to Salt Lake City....almost! He was there to play, have a good time & test his ability against some Idaho wind & the eye sight of the Rock Chucks, which is very, very good.
Like I said earlier, he would pass on the close shots so he could take the longer, 350 550 yd. shots & was making quick & accurate calculations & making the shots. The only problem we were seeing was the match grade bullets were killing slow & sometimes I was calling the shot high then we would see the Chuck slowly roll over just as he was about to shoot again.
Rock Chucks are tough & at a quarter mile & beyond I'm sure he actually hit some that I called high & the Chuck made it over a lava rock & died out of sight.
A varmint type bullet would work better but you have a bit of a learning curve when doing something new. Nothing new about hitting though, that came right out of the gate with 7 straight from tough shooting positions & most times just off of his soft shooting gear bag.
Probably only one other shooter in the country could do that.