No, Mach3 is the CNC controller software. I haven't found any CAD software worth dog spit yet.
Drilling the firing pin hole is no big deal; if you use a sprung pin the small hole is much shallower.
It's the profile of the locking lugs that stumps me. I could use the manual machines and make square lugs, but it requires a cam-operated or CNC fourth axis to cut the lugs... though I bet there are some geezers out there who could do it by eye with a file and half a plug of Red Man.