I bought these two years ago and they are the standard 125 grain smooth edge. The thing I noticed is that they have a cut-out in the blade and I bet that is what is causing the whistle. I bought another pack of them off of e-bay and they arrived last night. Difference is these are the Sabertooth model and they don't have a cut-out. I am going to shoot one this week to see if they whistle as well.

Red Bear