Recently finished a Kalifornia version a couple of months back with the fixed mag.  The weapon has about 250 rounds through it so it's still not really broken in yet.  When I pull the charging handle back it often doesn't push all the way forward.  I have to finish it by pushing it manually and it doesn't chamber the round.  Also, seems to happen more when I have 8-10 rounds in the mag compared to having only 4-5.  

Thanks in advance for the help.

V.Muth

Sorry guys, wrong board.  i will post in the trouble shooting board.