I got this from a correspondent who is in the CSI biz:"I just read your blog post about the new Gen 5 Glocks. Some info on the CSI front.
You are correct that previously, nearly any bullet fired from a Glock would not be identified to a specific pistol. However some time ago Glock started marketing barrels that were designed so the bullets could be matched back to a specific weapon.
http://blog.suarezinternational.com/...g-barrels.html