Hi,
I've made all sorts of locks from kits and castings and learned a great deal about lock physics from those projects because they allowed me to see how different makers designed their solutions to the problem of making reliable and efficient locks. For me, each set of castings from an original lock is a journey back in time to visit the mind and hand of the lock maker. Having said that, however, I also don't think building a lock is for everyone. Don Getz and the others are right if your goal is simply to build a working gun. The money saved from the lower cost of a kit is not worth the effort to build the lock. Alternatively, if your goal is to learn lock-making skills or no commercial lock will work for your project, then maybe a lock kit is right for you. How else will you learn?
Dennis's advice is good. Chamber's assembled gunmaker's lock gives you a lot of flexibility to shape the plate without needing to fit and heat treat the internal parts. I wish Jim would offer the same product but with an English-style pan, frizzen, and cock (although those can be fashioned from the parts he offers). The next level would be to make a Siler or Gunmaker's lock kit, in which you have clean cast parts that you fit and heat treat. You also have to drill and tap the holes except the critical tumbler and frizzen screw holes, and the springs are already hardened and tempered. The next step would be a set of castings from an original like those sold by the Rifle Shoppe and Blackley's. However, if you are looking to custom shape the plate and other outside components, castings from original locks may not be a good choice unless you find a set that is exactly what you want. Those locks were paired down to the finished shape by the original lock maker and there is usually little excess metal left to reshape.
dave
