I have never looked into this. However, you may want to consider actually taking a class in gunsmithing. Like learning the guitar, or whatever, hands on is the best way to learn. If you are honestly interested in learning how to do it right, see if a local college offers gunsmithing. If not, ask a REAL gunsmith if you can help him/her around their shop for free, just to learn how it's done. Explain that you don't plan to be competition for him, just do-it-yourself types of projects at home.