I have a opportunity to buy a CVA Hawken type rifle. I was told by my uncle it only needs a drum and nipple to be functional. I can get it for $25.00. It's .50 cal. I guess what I need to know is if it's worth the trouble to fix this rifle? If so how much cash will it take? Where can I get the parts. I plan on shooting PRB in it so I need to see if the rate of twist is ok. As far as I can tell it is in really good shape except for the drum and nipple needing replacement du to rusted in nipple.(Someone trashed the whole thing trying to take out the nipple.)