Stan,
I think everyone is looking in the wrong place. I think the shot cup was somehow held closed in place for the 23 yards, or close to it. Most likely by the shot cup petals being welded closed holding the load in place for most of the flight......i.e. manufacturing flaw of the shot cup.....
This could be a flaw in the shot cup as originally machine loaded by Remington.....unlikely that this happened after firing.....I've seen various brands of shot cups travel quite a distance without opening....freak, but it happens......
Best,
