Most likely worn out and not worth fixing. you would pay more to have it repaired than you can buy another used single shot for. Due to the safety issue I would just dispose of it and pick up something else. I had one that would actually fall apart upon firing at times, So worn out that the forend would come off in your hand and then the barrel would literally open and drop off the gun. I scrapped it before I got hurt.
CPL holder since 1991, NRA Lifetime Member, DU Member, NICET certified
"For those who would give up essential liberty to purchase a little temporary safety, deserve neither Liberty nor safety.—Ben Franklin.”