Welcome to the forum. I would check out what spring you currently have in your gun. There are several threads on it here to determine which is which. If you do not have the new one, call GLOCK as have them ship you on as _jb said.
I saw a thread on another forum yesterday where someone was selling the new spring.
Frustrates me when people try to take advantage of others.
I saw a thread on another forum yesterday where someone was selling the new spring.