Looking for someone who might enlighten me on a problem with this gun. I have three barrels. The gun bolt only retracts and extracts the shell when I use one of these barrels. When either one of the other two barrels are installed, the gun fires the cartridge in the chamber, but the bolt does not retract and eject the shell and chamber a new cartridge. In reading the U. K. report on Breda 30, they refer to this problem as a worn barrel and the solution is to have the barrel tested. From a visual observation, I do not see any appreciable signs of wear on the barrel, but I realize there are tight tolerances in the fermature and the barrel lockup. Anybody ever encounter this problem and is there any remedy to make the two barrels usable? Thanks for all help