Using factory SAAMI spec rounds, there never was a problem. There has been continual refinement, but not resulting from rampant failure from spec rounds. Older barrels were quite adequate, but not as able to compensate for overcharged rounds or reloaded brass. I've owned and been issued .40 glocks since they came out, and despite heavy agency and personal shooting, never encountered or observed a problem.
Originally Posted by digilo
Is there a .40 barrel that is supported, and reliable as stock? Or is support at the expense of reliability in the .40?