Re: 600 Yards with a 1911?
I have never shot a 1911 (or anything else except an M1 rifle at 600 yards. But I have fired a .357 S&W Model 28 6" at 150 yards, and I do know there is no way he could have a front sight marked or notched for 600 yards. At 150 yards, I was holding the base of the front sight (where it joins the barrel rib) even with the top of the rear sight. I have no idea how much holdover I would need at 600 Yards, but it would be a lot of guess and by golly unless I had a fixed aiming point at the right distance above the target to give me a decent sight picture.
I have no doubt that a .45 pistol can shoot 600 yards and hit something. But I am highly skeptical that even on that big target it can be done with any consistency, and certainly not with ammunition that varies 150 fps in a box. Of course, I don't have one of those magic pistols.