My son filmed this kill in Boone this weekend. As he was editing the footage he was able to step frame by frame (figuratively) through and catch the pellets in flight. Here is a screenshot.
I think he said it was 40 yards. The guy he was filming works for Winchester so they were some special Winchester shells with a special buffer to cut down on deformed shot in the bottom of the cup.
That's really cool. That takes a high frame rate (60p?), a lot of light, and just the right angle to catch the glare off those pellets. I've never seen that before.