I have a Meriden Model 15 pump action tube fed 22 rifle that was my grandpa's. I inherited it when he passed away. The blueing is gone and the metal needs some work. The biggest problem is probably the rifling in the barrel. The bullets appear to tumble (based on the paper target). Is rifling something that is repairable? If yes, can anyone recommend a gunsmith that could do the repairs. I'm very interested in an estimated cost to repair the rifle if it's repairable. I don't think the gun is worth much but it has sentimental value and I'd love to get it back into good condition.