I have a model 12 varmit that is very accurate and has or had a great trigger pull. Lately it has started malfuctioning. Occasionally the accurelease blade will not depress with any amount of pressure that I can apply with my finger and the gun will not fire. Ocasionally the sear safety will engage when the accurelease blade is depressed but before my finger touches the trigger. Since that has started happening I have ben very careful to depress the blade straight back fully before my finger touches the trigger. That does not help the problem. This has been gradually getting worse and now results in about one malfunction in five shots. It is more frequent if I cycle the bolt rapidly but will also happen if I cycle the bolt slowly. The trigger has not been modified or adjusted since it left the factory. It gages 22 oz. on my pull gage. Other than increasing the pull weight is there anything that I might try before having a gunsmith look at it? I am fairly proficient in minor gun work and some trigger work but I would not consider myself a gunsmith.