Need help with a problem with my M-1 Carbine...

Maybe I am not seeing the obvious but I am still looking for you guys to point it out.

I have an IAI M-444 (this Israeli companys version of the Carbine) that will not full seat a cartridge in the chamber. The bolt will not go into battery because of it. Last year it was loaned to a friend who does WWII "Living History" to shoot blanks (both plastic and brass). Last month I finally got around to fully dis-assembling the rifle with the exception of taking the barrel off of the reciever and cleaned it. Now I cannot even get the blanks to chamber fully. I have scrubbed the bore and tried as best I could to get the chamber clean.

With a bore light I cannot spot any obstructions in the barrel or the chamber but then again it goes back to not beeing able to see the chamber fully because of its design.

Any suggestions?