MIKE GEORGE says: The most common cause of cyclic failures in all semi-autos is muck. So, if you haven’t done so already, give it a really thorough clean, paying particular attention to the gas ports, the gas piston and cylinder, the magazine tube, and the area around the bolt.

Also check that the piston seals are intact, and the bolt follower, and the spring to which it is attached, are undamaged and working smoothly.

Strip-down, cleaning, and reassembly instructions are given in the service manual which should have been supplied with the gun.

If you don’t have a manual, you can download one at It is 26 pages long, and well worth reading.

Got a question? Contact: or Sporting Gun, PO Box 157, Stamford, Lincolnshire PE9 9FU