Thank's for reply @Alias1983 !
I have fix my missfeed issues but now I've got a problem to reassembling the gun, when I'm puting back the hanguard, the pump's arms are catch by a little silver hook and I can't push the handguard/pump to is initial position on the magazine tube. Anyone knows how to fix this thing ?
The piece who's catching the arms each time, is the little silver piece, wich is screwed on the body by a black screw, on this photo :
I hope you have understood my question, that's diffcult for a frenchie !