I'm not sure what to take from that. A hay bale caused the expanders to exand to that degree or was it the frozen ground? Where abouts are you DDH? How hard frozen is the ground? Even here we didn't get much of a ground freeze this year due to an early snow that never left.

Try ramming them through a 5 gal pail of packed damp earth to see how they expand and compare them then. A hay bale to form an opinion on expansion???

Just curious you know??