Jerry Miculek's one of the best ambassadors for the shooting sports, the Second Amendment, and gun ownership we've ever had, and he's a fantastic shot and gun handler, no doubt about it. He's in a class by himself.
I can't get real excited about this, though, especially if this is being compared to Keith's feat of marksmanship.
Elmer Keith was using what was basically a plain ol' revolver. No sandbag rests, no high tech sights, and he didn't have a buddy with a high power scope spotting for him. And I'm not sure he was shooting at a stationary target, either, with all the time in the world to line up the shot.
I'm not belittling Miculek's shooting, but give him a plain ol' .44 with factory sights, let him use his handloads, and let's see how many tries it takes to puncture that balloon at 1000 yards. Or 600 yards. Maybe he's already done it, I don't know. If so, more power to him.