I agree that it might be the extractor or maybe the springs if the Glock is used.
For more custom work or repair details about Glock series pistols. See
www.Glock.com www.glockbooks.com www.customizemyglock.com www.glockstore.com www.paladin-press.com .
To keep it clean with a high quality CLP like LPX, Gunzilla or Weaponshield is smart too.