I figure smaller shot means you could probably get all 3 of those jsckasses at one time.....just a few pellets apiece would get the message across.
It’s not the shot size that determines the pattern, it’s the choke or lack there of. I have seen reference to a special operations choke that spreads the shot horizontally. Don’t know if that ever made it past experimental.
On the magnetic extraction of the pellets, make sure they are facing the direction of the shot entry so they go out the entry holes & not the other way.