More info from my odd WK. If I close of the port holes completely, it still fires. So for mine, unscrewing the the set-screw all the way to the front of the gun, there is lots of volume for the gas to go, and it won't cycle. Then I screw in the set-screw towards the port holes, till she just cycles. It works great. My WK180c barely jumps when I fire it now. The set-screw is around halfway between the port-holes and front of the gas block. .223 PMC BRONZE was used for setting, as it's the weakest round I shoot through the gun.