For the carriage I have given thought. I have looked at recoil and such. I know it will be heavy. I have more experience with wood than I do barrel making and powder chamber fab. If it ends up being too heavy I may go with all steel carriage. I have a 5x10 CNC plasma table and a 4x8 router CNC to help me with the build. I am just really concerned with the Chamber and the barrel because I have never done it.