I was shooting my Marlin Golden 39A Mountie a few days ago. Everything was good. I was hitting every thing I was shooting at (golf balls, empty shotgun shells, and smaller bits of debris) at 25 yards. Then after a shot, I opened the lever to chamber another round. When I tried to close it, it wouldn't close.
When I got home, I took it apart. I discovered that the carrier rocker spring had broken. I got on the internet and found one at Numrich Gun Parts. It cost $2.70. The shipping cost me more than the part.
The action on that gun is so simple, yet extremely rugged. It is very easy to repair.
I really can't complain. I bought the gun in 1970 and I can only guess at how many tens of thousands of rounds I have fired in it. I taught my son to shoot with it.