The 58 gas system, is practically the same one, that Winchester used when they made the 1400, I have had them both apart for cleaning side by side. Usually a good cleaning of the gas system and the internals, is all they need to work. No one ever took the time to maintain these fine old guns correctly. The 48 was recoil operated and did not require much upkeep, and I think a lot of folks thought the same of the 58, just my two cents.