600 yards with a 44 mag in a handgun or a rifle. Either way that’s a hell of a shot. But Elmer Keith (was/is? he would have to be in his 90s by now)a hell of a shooter. 44 mag trajectory is like a fast pitch softball at over 100 yards and not very flat at 100 yards. I love the 270 Win for hunting. I have a 30.06 but it seldom comes out of the gun safe except for cleaning and verifying the scopes accuracy. I used to have a 44 mag Marlin lever action rifle.
I had a .45 Marlin Lever action, with which I could ring a steel target reliably at 400 yards.
I bought it for research, as I was designing a rifle that could fire any of 5.56x45, 7.62x51, or .45 ACP with a change in barrel and magazine.
I particularly liked the notion of an assault rifle that had a laser range finder, automatic super-elevation, and a silenced .45ACP option for taking out guard posts or listening/observation posts.
Keith’s shot was with a pistol! Again, the animal was already wounded, so the sporting thing to do was to try to put it down.