If the WWB you're referring to is the 100 round Value Pak, you should know that this ammo has a documented history of undersize rim diameters in 9mm. I had three failures to extract with this 9mm ammo in a Bersa pistol, all three rounds from the same box. All three remained completely in the chamber but readily fell out when the gun was pointed upwards, indicating the extractor had ridden right over the rim without engaging it. I've fired a 600 round mix of other ammo in this gun without a failure. I haven't heard of it in the .40, but on the basis of this experience, if you want a good diagnosis, switch ammo. The Value Pack could be giving you a false reading.
I decline to blame the gun for a failure when shooting any WW Value Pack ammo. FWIW
Jer