Not sure if this will help but mine would misfire every 4 or 5 rounds and it turned out that the barrel nut was loose. Tightened it up and it has functioned flawlessly ever since. There is a cover over the top where the rear sight is mounted so you can't see the nut without removing the wooden forearm. You may have to drift out the rear sight and remove the cover as well. I don't remember. If you look at the bottom and their is a gap where the wooden forearm meets the metal of the receiver then this is likely one of your problems.
Also the 190 was not designed to feed .22 shorts. Long or long rifle only. I don't know if you can even buy .22 longs anymore. So basically long rifle only.
The cocking handle is indeed intended to push in to lock the bolt open. Possibly a burr or something keeping it from retracting fully? I would try just polishing it up and see what happens.
Last edited by slappy; January 7, 2013 at 10:56 AM.