These are simple enough that about any Competent gunsmith could do that. You can do it yourself, probably.
Take the recoil pad or buttplate off and take off the buttstock. Spray the inside of the receiver from the back with brake cleaner, let it soak, and do it again several times. Then lubricate lightly with a premium gun oil.
As erich said, it might not be getting cocked. If nothing is damaged inside this should cure that condition.
