If it is extracting, I could almost live with BTF...not really, but I'm being generous...but having failures to extract, with any weight bullet, is just unacceptable in a defensive pistol. I never thought I'd hear folks using 1911 excuses for a stock Glock.Thanks for all the input, everyone. This gun isn't just throwing brass at me, it's having failures to extract, and extracting to the left and such. It ran like a top with 124gr. ammo, so I know that's a factor.
It doesn't matter what weight bullet they test them with. This isn't some collector piece or some super exotic pistol...it is designed as a working gun. Also 115gr bullets aren't uncommon. All 9mm service pistols should work with any factory bullet within the range of 115gr-147gr.
If you aren't aware of the issue with late Gen 3 and Gen 4 9mm Glocks, there is a lot of reading available on the internet. The Cliff Notes version is that the extractor is losing control of the casing after it is extracted from the chamber after being fired. The empty case is floating in the slide, moving to the rear through inertia, supported by the next round in the magazine. When the slide stops, the case is bouncing off the breechface, into the front of the ejection port, and out the top toward the shooter.
There is a easy test to see if your extractor is controlling the case after extraction. Just load a round from the magazine, remove the magazine, and fire the round. If the round drops out the magazine well, it wasn't being held by the extractor