Delrin has a mellower sound that acrylic.Wood is even more mellow. I only use delrin for my calls....tough as nails, tone doesn't change due to weather[wood does] and a nicer tone than acrylic, IMO. Delrin isn't quit as loud as acrylic, but if you go to higher pitched call [pip- sqeek] it increases volume and the distance your call will carry.
Causing permenant flight delays
Callin' 'em in and knockin' 'em down