Most expandables should have directions on the minimum feet-per-second on the package if it's a concern. If I were shooting about 220fps, I'd opt for a smaller style head; something like the Rocket Mini-blaster or Wolverine, because I think it would take less energy to get a smaller head to operate more easily than something larger in it's class. Last time I shot a mini-Rocket I 'bout cut a grey squirrel completely in half.

iSnipe