Not guaranteed to work.
Caveat emptor
Unload your weapon three times and then go to another room that doesn't have ammo in it before starting. I'm not liable for stuff you break nor if your Glock isn't 1000% reliable afterwards and therefore you die on the streets.
- Install a 30274 ejector $7, even if your 9mm Glock isn't a Gen4.
- Install a White Sound H.R.E.D $15
- Polish the top and bottom horizontal surfaces of the extractor with something light like say toothpaste and this Dremel wheel. You want the extractor to slide in out and smoothly, like using cornstarch in a Zentai suit. Just a light polish.
- Get the latest RSA (recoil spring assembly) by calling Glock's customer service or ordering online
- Test fire. The best way to see if you've fixed the problem is to use weaker range ammo, not high powered NATO or carry ammo
- If you still have the problem, grab an APEX extractor and install per the instructions. I recommend just ordering and installing this, the HRED, and the ejector (if you don't have it) along with checking with Glock to make sure you have the latest and greatest RSA (recoil spring adapter) in order to save yourself time.
These steps have worked for me and others I know. My Gen4 G17 gobbled up Wolf, Tula, Blazer, carry ammo, and WWB with aplomb and good ejection last weekend in the rain and sleet at the GreenOps Defensive Pistol I class.