I find that every half dollar I use fits well (Walking Liberty, Barber, Franklin, Kennedy, etc.).
And in the event they don't fit, Bacon Magic includes quite a few inserts that keep a thinner half
dollar in place. I haven't had to use one, though.
As far as the chop cup, it's quite
convenient to have this size. You can bring it anywhere. The balls are great quality.
Great
device.