Please try these basic trouble shooting tips before requesting service: *Please make sure the recoil spring is installed correctly. The narrow end of the spring MUST be on the guide rod first…pointing towards the rear of the gun. If it is not, this will cause feeding, extraction and firing issues. *Like many .22 LR’s, Mosquito’s can be sensitive to ammunition used and to cleanliness and lubrication. Be sure your Mosquito is cleaned and lubricated regularly and before the first use. *There is a lubrication port on the right side of the slide for the extractor, be sure you add a drop of lube in this hole every hundred rounds or so. Make sure the gun is very clean. *Some Mosquito’s benefit from a break-in period. *Be sure to use factory recommend ammunition – CCI Mini-Mags. Winchester Super-X, Remington Golden Bullet, Federal High Velocity etc…also usually work well.