The Glocks have a polymer frame that makes it lighter. So if you limp-wrist it, the expended case will stovepipe after you fire. This happens with other polymer frame pistols. If you are properly trained, you don't limp-wrist while firing, whether with a polymer frame or metal frame pistol.
I've fired hundreds of rounds through Glocks, no problems.
I've fired hundreds of rounds through Glocks, no problems.