GLOCK Addressing the Gen 4 Spring Issue.
From Pistol-Training.com, great news indeed.
"If you’ve been following the tale of gen4 Glocks, you know that in just over a year the company has tried a variety of different recoil spring assembly (RSA) variants trying to alleviate various problems users have experienced. Adding to the trouble has been the need for different RSAs for guns with and without a properly counterbored spring box (aka, “nose ring”).
Finally, they’ve got it all figured out and Glock is announcing a free “exchange program” for any gen4 Glock owner. There is now just one RSA per model, regardless of whether the slide was counterbored for the RSA or not. As someone who owns two non-counterbored Glocks, I can tell you that is good news because finding the non-counterbored-only spring (0-2-1) is almost impossible.
All you need to do is contact Glock at 1-877-745-8523 with your serial number and model number. They will send you a replacement spring and a pre-addressed envelope to return the old one. For details, you can visit TeamGlock.com.
Tip of the hat to pistol-forum.com member hvd229 for initially posting the info!"